5% ORIGINAL ISSUE DISCOUNT UNSECURED CONVERTIBLE DEBENTURE DUE __________, 2013

EXHIBIT 4.1

NEITHER THIS SECURITY NOR THE SECURITIES INTO WHICH THIS SECURITY IS CONVERTIBLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD OR OTHERWISE TRANSFERRED, PLEDGED OR HYPOTHECATED EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT OR PURSUANT TO AN AVAILABLE EXEMPTION FROM, OR IN A TRANSACTION NOT SUBJECT TO, THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT AND IN ACCORDANCE WITH APPLICABLE STATE SECURITIES LAWS AS EVIDENCED BY A LEGAL OPINION OF COUNSEL TO THE TRANSFEROR TO SUCH EFFECT, THE SUBSTANCE OF WHICH SHALL BE REASONABLY ACCEPTABLE TO THE COMPANY.

Original Issue Date: __________, 2012

$_______________

5% ORIGINAL ISSUE DISCOUNT UNSECURED CONVERTIBLE DEBENTURE

DUE __________, 2013

THIS 5% ORIGINAL ISSUE DISCOUNT UNSECURED CONVERTIBLE DEBENTURE is one of a series of duly authorized and validly issued 5% Original Issue Discount Unsecured Convertible Debentures of SpectraScience, Inc., a Minnesota corporation, (the “Company”), having its principal place of business at 00000 Xxxxxxxx Xxxxxx Xx., Xxxxx 00, Xxx Xxxxx, Xxxxxxxxxx 00000, designated as its 5% Original Issue Discount Unsecured Convertible Debenture due _______________, 2013 (this debenture, the “Debenture” and, collectively with the other debentures of such series, the “Debentures”).

FOR VALUE RECEIVED, the Company promises to pay to ________________________ or its registered assigns (the “Holder”), or shall have paid pursuant to the terms hereunder, the principal sum of $_______________ on __________, 2013 (the “Maturity Date”) or such earlier date as this Debenture is required or permitted to be repaid as provided hereunder, and to pay interest to the Holder on the aggregate unconverted and then outstanding principal amount of this Debenture in accordance with the provisions hereof. This Debenture is subject to the following additional provisions:

Section 1. Definitions. For the purposes hereof, in addition to the terms defined elsewhere in this Debenture, (a) capitalized terms not otherwise defined herein shall have the meanings set forth in the Purchase Agreement and (b) the following terms shall have the following meanings:

"Affiliate” means any Person that, directly or indirectly through one or more intermediaries, controls or is controlled by or is under common control with a Person, as such terms are used in and construed under Rule 405 under the Securities Act.

“Alternate Consideration” shall have the meaning set forth in Section 5(b).

“Bankruptcy Event” means any of the following events: (a) the Company or any Significant Subsidiary (as such term is defined in Rule 1-02(w) of Regulation S-X) thereof commences a case or other proceeding under any bankruptcy, reorganization, arrangement, adjustment of debt, relief of debtors, dissolution, insolvency or liquidation or similar law of any jurisdiction relating to the Company or any Significant Subsidiary thereof, (b) there is commenced against the Company or any Significant Subsidiary thereof any such case or proceeding that is not dismissed within 60 days after commencement, (c) the Company or any Significant Subsidiary thereof is adjudicated insolvent or bankrupt or any order of relief or other order approving any such case or proceeding is entered, (d) the Company or any Significant Subsidiary thereof suffers any appointment of any custodian or the like for it or any substantial part of its property that is not discharged or stayed within 60 calendar days after such appointment, (e) the Company or any Significant Subsidiary thereof makes a general assignment for the benefit of creditors, (f) the Company or any Significant Subsidiary thereof calls a meeting of its creditors with a view to arranging a composition, adjustment or restructuring of its debts or (g) the Company or any Significant Subsidiary thereof, by any act or failure to act, expressly indicates its consent to, approval of or acquiescence in any of the foregoing or takes any corporate or other action for the purpose of effecting any of the foregoing.

“Beneficial Ownership Limitation” shall have the meaning set forth in Section 4(c).

“Business Day” means any day except any Saturday, any Sunday, any day which shall be a federal legal holiday in the United States or any day on which banking institutions in the State of New York are authorized or required by law or other governmental action to close.

“Buy-In” shall have the meaning set forth in Section 4(d)(iv).

“Change of Control Transaction” means the occurrence after the date hereof of any of either (a) an acquisition after the date hereof by an individual or legal entity or “group” (as described in Rule 13d-5(b)(1) promulgated under the Exchange Act) of effective control (whether through legal or beneficial ownership of capital stock of the Company, by contract or otherwise) of in excess of 60% of the voting securities of the Company (other than by means of conversion or exercise of the Debentures and the Securities issued together with the Debentures), (b) the Company merges into or consolidates with any other Person, or any Person merges into or consolidates with the Company and, after giving effect to such transaction, the shareholders of the Company immediately prior to such transaction own less than 50% of the aggregate voting power of the Company or the successor entity of such transaction, or (c) the Company sells or transfers all or substantially all of its assets to another Person and the shareholders of the Company immediately prior to such transaction own less than 50% of the aggregate voting power of the acquiring entity immediately after the transaction, and a replacement at one time or within a three year period of more than one-half of the members of the Board of Directors which is not approved by a majority of those individuals who are members of the Board of Directors on the date hereof (or by those individuals who are serving as members of the Board of Directors on any date whose nomination to the Board of Directors was approved by a majority of the members of the Board of Directors who are members on the date hereof), or (e) the execution by the Company of an agreement to which the Company is a party or by which it is bound, providing for any of the events set forth in clauses (a) through (d) above.

“Common Stock Equivalents” means any securities of the Company or the Subsidiaries which would entitle the holder thereof to acquire at any time Common Stock, including, without limitation, any debt, preferred stock, rights, options warrants, or other instrument that is at any time convertible into or exercisable or exchangeable for, or otherwise entitles the holder thereof to receive Common Stock.

“Conversion” shall have the meaning ascribed to such term in Section 4.

“Conversion Date” shall have the meaning set forth in Section 4(a).

“Conversion Price” shall have the meaning set forth in Section 4(b).

“Conversion Schedule” means the Conversion Schedule in the form of Schedule 1 attached hereto.

“Conversion Shares” means, collectively, the shares of Common Stock issuable upon conversion of this Debenture in accordance with the terms hereof.

“Debenture Register” shall have the meaning set forth in Section 2(c).

“Event of Default” shall have the meaning set forth in Section 8(a).

“Equity Conditions” means, during the period in question, (a) the Company shall have duly honored all conversions by virtue of one or more Notices of Conversion of the Holder, if any, (b) the Company shall have paid all liquidated damages and other amounts owing to the Holder in respect of this Debenture, (c) the Common Stock is trading on a Trading Market and all of the shares issuable pursuant to the Transaction Documents are listed or quoted for trading on such Trading Market (and the Company believes, in good faith, that trading of the Common Stock on a Trading Market will continue uninterrupted for the foreseeable future), (d) there is a sufficient number of authorized but unissued and otherwise unreserved shares of Common Stock for the issuance of all of the shares issuable pursuant to the Transaction Documents, (e) there is no existing Event of Default or no existing event which, with the passage of time or the giving of notice, would constitute an Event of Default, (f) the issuance of the shares in question to the Holder would not violate the limitations set forth in Section 4(c) herein provided that any shares proposed to be issued that would cause a violation of Section 4(c) will be automatically deemed canceled by the Company and upon such cancellation this clause (f) shall be satisfied, (g) there has been no public announcement of a pending or proposed Fundamental Transaction or Change of Control Transaction that has not been consummated, and (h) the Holder is not in possession of any information provided by the Company that constitutes, or may constitute, material non-public information other than information required to be provided by the Company under the Subscription Agreement.

“Exchange Act” means the Securities Exchange Act of 1934, as amended, and the rules and regulations promulgated thereunder.

“Exempt Issuance” means the issuance of (a) shares of Common Stock or options to employees, officers, consultants, advisors or directors of the Company pursuant to any stock or option plan duly adopted for such purpose by a majority of the existing members of the Board of Directors or a majority of the members of a committee of directors established for such purpose, (b) securities upon the exercise or exchange of or conversion of any Securities issued hereunder and/or other securities exercisable or exchangeable for or convertible into shares of Common Stock issued and outstanding on the date of this Agreement, provided that such securities have not been amended since the date of this Agreement to increase the number of such securities or to decrease the exercise, exchange or conversion price of such securities, (c) securities issued pursuant to acquisitions or strategic transactions approved by a majority of the disinterested directors of the Company, provided that any such issuance shall only be to a Person which is, itself or through its subsidiaries, an operating company in a business synergistic with the business of the Company and in which the Company receives benefits in addition to the investment of funds, but shall not include a transaction in which the Company is issuing securities primarily for the purpose of raising capital or to an entity whose primary business is investing in securities, and (d) issuances of restricted securities issued by the Company from time to time for the payment of services or to vendors, which shares are not issued for cash consideration in an amount not to exceed 750,000 shares per calendar year.

“Fundamental Transaction” shall have the meaning set forth in Section 5(b).

“Interest Notice Period” shall have the meaning set forth in Section 2(a).

“Interest Payment Date” shall have the meaning set forth in Section 2(a).

“Interest Share Amount” shall have the meaning set forth in Section 2(a).

"Interest Rate" shall mean sixteen percent (16%) per annum.

“Late Fees” shall have the meaning set forth in Section 2(d).

“Liens” means a lien, charge, security interest, encumbrance, right of first refusal, preemptive right or other restriction.

“Mandatory Default Amount” means the sum of (a) 100% of the outstanding principal amount of this Debenture, plus 100% of accrued and unpaid interest hereon, and (b) all other amounts, costs, expenses and liquidated damages due in respect of this Debenture.

“New York Courts” shall have the meaning set forth in Section 9(d).

“Notice of Conversion” shall have the meaning set forth in Section 4(a).

“Original Issue Date” means the date of the first issuance of the Debentures, regardless of any transfers of any Debenture and regardless of the number of instruments which may be issued to evidence such Debentures.

“Permitted Indebtedness” means (a) the indebtedness evidenced by the Debentures and any prior issued Debentures (b) lease obligations and purchase money indebtedness of up to $500,000, in the aggregate, incurred in connection with the acquisition of capital assets and lease obligations with respect to newly acquired or leased assets, (c) trade account payables and expenses incurred in the ordinary course of business, (d) wages and other compensation due to employees and agents for services performed, (e) liabilities for taxes not yet due, (f) liabilities for customer deposits, (g) indebtedness existing on the date hereof, and (h) indebtedness of the Company to any Subsidiary and of any Subsidiary to the Company or any other Subsidiary.

“Permitted Lien” means the individual and collective reference to the following: (a) Liens for taxes, assessments and other governmental charges or levies not yet due or Liens for taxes, assessments and other governmental charges or levies being contested in good faith and by appropriate proceedings for which adequate reserves (in the good faith judgment of the management of the Company) have been established in accordance with GAAP; (b) deposits or pledges to secure bids, tenders, contracts, leases, statutory obligations, performance bonds, surety and appeal bonds and other obligations of like nature arising in the ordinary course of the Company’s business; (c) deposits or pledges to secure obligations under workers’ compensation, social security or similar laws, or under unemployment insurance or general liability or product liability insurance; (d) Liens imposed by law which were incurred in the ordinary course of the Company’s business, such as carriers’, warehousemen’s and mechanics’ Liens, statutory landlords’ Liens, and other similar Liens arising in the ordinary course of the Company’s business, and which (x) do not individually or in the aggregate materially detract from the value of such property or assets or materially impair the use thereof in the operation of the business of the Company and its consolidated Subsidiaries or (y) are being contested in good faith by appropriate proceedings, which proceedings have the effect of preventing for the foreseeable future the forfeiture or sale of the property or asset subject to such Lien; and (e) Liens incurred in connection with Permitted Indebtedness under clause (a) thereunder; and (f) Liens incurred in connection with Permitted Indebtedness under clause (b) thereunder, provided that such Liens are not secured by assets of the Company or its Subsidiaries other than the assets so acquired or leased; (g) Liens existing on the date hereof; (h) any attachment or judgment Lien not constituting an Event of Default; and (i) easements, rights of way, restrictions, and other similar charges or encumbrances not interfering in any material respect with the ordinary conduct of the business of the Company.

“Person” means an individual or corporation, partnership, trust, incorporated or unincorporated association, joint venture, limited liability company, joint stock company, government (or an agency or subdivision thereof) or other entity of any kind.

“Purchase Agreement” means the Subscription Agreement, dated as of __________, 2012 among the Company and the original Holders, as amended, modified or supplemented from time to time in accordance with its terms.

“Securities Act” means the Securities Act of 1933, as amended, and the rules and regulations promulgated thereunder.

“Share Delivery Date” shall have the meaning set forth in Section 4(d)(ii).

“Subsidiary” shall have the meaning set forth in the Purchase Agreement.

“Trading Day” means a day on which the New York Stock Exchange is open for business.

“Trading Market” means the following markets or exchanges on which the Common Stock is listed or quoted for trading on the date in question: the NYSE AMEX LLC, the Nasdaq Capital Market, the Nasdaq Global Market, the Nasdaq Global Select Market, the New York Stock Exchange, the OTC Bulletin Board or the other OTC markets, including the OTCQX, OTCQB and OTC Pink Markets.

“Transaction Documents” shall have the meaning set forth in the Purchase Agreement.

Section 2. Interest.

a) Payment of Interest in Cash or Kind. The Company shall pay interest to the Holder at the Interest Rate on the aggregate principal amount of the principal being converted on any Conversion Date (as to that principal amount then being converted), and on the Maturity Date (each such date, an “Interest Payment Date”) (if any Interest Payment Date is not a Business Day, then the applicable payment shall be due on the next succeeding Business Day), in cash or, at the Company’s option, in duly authorized, validly issued, fully paid and non-assessable shares of Common Stock (the dollar amount to be paid in shares, the “Interest Share Amount”) or a combination thereof; provided, however, that payment in shares of Common Stock on account of interest may only occur if (i) all of the Equity Conditions have been met (unless waived by the Holder in writing) during the 2 Trading Days immediately prior to the applicable Interest Payment Date (the “Interest Notice Period”) and through and including the date such shares of Common Stock are actually issued to the Holder, (ii) the Notice of Conversion delivered by the Holder to Company affirms that the issuance of the Conversion Shares on account of principal and interest will not violate Section 4(c) hereunder. To the extent that any such issuance of Conversion Shares on account of interest under this Section 2(a) would violate section 4(c), such interest shall either be paid in cash or at the Company's election deferred and paid in Conversion Shares at the next Conversion Date.

b) Company’s Election to Pay Interest in Cash or Shares of Common Stock. Subject to the terms and conditions herein, the decision whether to pay interest hereunder in cash, shares of Common Stock or a combination thereof shall be at the sole discretion of the Company.

c) Interest Calculations. Interest on the principal balance of this Note shall be calculated on the basis of a 360-day year, consisting of twelve 30 calendar day periods, and shall accrue daily commencing on the Original Issue Date until payment in full of the outstanding principal, together with all accrued and unpaid interest, liquidated damages and other amounts which may become due hereunder, has been made. Interest shall cease to accrue with respect to any principal amount converted, provided that, the Company actually delivers the Conversion Shares within the time period required by Section 4(d)(ii) herein. Interest hereunder will be paid to the Person in whose name this Debenture is registered on the records of the Company regarding registration and transfers of this Debenture (the “Debenture Register”). Except as otherwise provided herein, if at any time the Company pays interest partially in cash and partially in shares of Common Stock to the holders of the Debentures, then such payment of cash shall be distributed ratably among the holders of the then-outstanding Debentures based on their (or their predecessor’s) initial purchases of Debentures pursuant to the Purchase Agreement.

d) Late Fee. All overdue accrued and unpaid interest to be paid hereunder shall entail a late fee at an interest rate equal to the lesser of 18% per annum or the maximum rate permitted by applicable law (the “Late Fees”) which shall accrue daily from the date such interest is due hereunder through and including the date of actual payment in full.

e) Prepayment. Except as otherwise set forth in this Debenture, the Company may not prepay any portion of the principal amount of this Debenture without the prior written consent of the Holder.

Section 3. Registration of Transfers and Exchanges.

a) Different Denominations. This Debenture is exchangeable for an equal aggregate principal amount of Debentures of different authorized denominations, as requested by the Holder surrendering the same. No service charge will be payable for such registration of transfer or exchange.

b) Investment Representations. This Debenture has been issued subject to certain investment representations of the original Holder set forth in the Purchase Agreement and may be transferred or exchanged only in compliance with the Purchase Agreement and applicable federal and state securities laws and regulations.

c) Reliance on Debenture Register. Prior to due presentment for transfer to the Company of this Debenture, the Company and any agent of the Company may treat the Person in whose name this Debenture is duly registered on the Debenture Register as the owner hereof for the purpose of receiving payment as herein provided and for all other purposes, whether or not this Debenture is overdue, and neither the Company nor any such agent shall be affected by notice to the contrary.

Section 4. Conversion.

a) Voluntary Conversion. At any time after the Original Issue Date until this Debenture is no longer outstanding, this Debenture shall be convertible, in whole or in part, into shares of Common Stock at the option of the Holder, at any time and from time to time (subject to the conversion limitations set forth in Section 4(c) hereof). The Holder shall effect conversions by delivering to the Company a Notice of Conversion, the form of which is attached hereto as Annex A (each, a “Notice of Conversion”), specifying therein the principal amount of this Debenture to be converted and the date on which such conversion shall be effected (such date, the “Conversion Date”). If no Conversion Date is specified in a Notice of Conversion, the Conversion Date shall be the date that such Notice of Conversion is actually delivered hereunder. To effect conversions hereunder, the Holder shall not be required to physically surrender this Debenture to the Company unless the entire principal amount of this Debenture, plus all accrued and unpaid interest thereon, has been so converted. Conversions hereunder shall have the effect of lowering the outstanding principal amount of this Debenture in an amount equal to the applicable conversion. The Holder and the Company shall maintain records showing the principal amount(s) converted and the date of such conversion(s). The Company may deliver an objection to any Notice of Conversion within 1 Business Day of delivery of such Notice of Conversion. In the event of any dispute or discrepancy, the records of the Company shall be controlling and determinative in the absence of manifest error.

b) Conversion Price. The conversion price in effect on any Conversion Date shall be equal to $0.099, subject to adjustment herein (the “Conversion Price”).

c) Conversion Limitations. Holder shall not have the right to convert any portion of this Debenture, pursuant to Section 4 or otherwise, to the extent that after giving effect to such issuance after conversion the Holder (together with the Holder’s Affiliates, and any other person or entity acting as a group together with the Holder or any of the Holder’s Affiliates), would beneficially own in excess of the Beneficial Ownership Limitation (as defined below). For purposes of this Section beneficial ownership shall be calculated in accordance with Section 13(d) of the Exchange Act and the rules and regulations promulgated thereunder. Holder is solely responsible for any schedules required to be filed in accordance therewith. The Company shall have no obligation to verify or confirm the accuracy of such filings. In any case, the number of outstanding shares of Common Stock shall be determined after giving effect to the conversion or exercise of securities of the Company, including this Debenture, by the Holder or its Affiliates since the date as of which such number of outstanding shares of Common Stock was reported. The “Beneficial Ownership Limitation” shall be 4.99% of the number of shares of the Common Stock outstanding immediately after giving effect to the issuance of shares of Common Stock issuable upon exercise of this Debenture. The Holder, upon not less than 61 days’ prior notice to the Company, may increase or decrease the Beneficial Ownership Limitation provisions of this Section 4(c), provided that the Beneficial Ownership Limitation in no event exceeds 9.99% of the number of shares of the Common Stock outstanding immediately after giving effect to the issuance of shares of Common Stock upon exercise of this Debenture held by the Holder and the provisions of this Section 4(c) shall continue to apply. Any such increase or decrease will not be effective until the 61^st day after such notice is delivered to the Company. The limitations contained in this paragraph shall apply to a successor holder of this Debenture.

d) Mechanics of Conversion.

i. Conversion Shares Issuable Upon Conversion of Principal and Interest Amount. The number of Conversion Shares issuable upon a conversion hereunder shall be determined by the quotient obtained by dividing (x) the outstanding principal amount and accrued but unpaid interest of this Debenture to be converted by (y) the Conversion Price.

ii. Delivery of Certificate Upon Conversion. Not later than four Trading Days after each Conversion Date (the “Share Delivery Date”), the Company shall deliver, or cause to be delivered, to the Holder (A) a certificate or certificates representing the Conversion Shares which, on or after the six month anniversary of the Original Issue Date, shall be free of restrictive legends and trading restrictions (other than those which may then be required by the Purchase Agreement or applicable law) representing the number of Conversion Shares being acquired upon the conversion of this Debenture and (B) a bank check in the amount of accrued and unpaid interest (if the Company has elected or is required to pay accrued interest in cash). On the six month anniversary of the Original Issue Date, the Company shall use its commercially reasonable efforts to deliver any certificate or certificates required to be delivered by the Company under this Section 4(d) electronically through the Depository Trust Company or another established clearing corporation performing similar functions.

iii. Partial Liquidated Damages. If the Company is obligated to and fails for any reason to deliver to the Holder such certificate or certificates pursuant to Section 4(d)(ii) by the fifth Trading Day after the Conversion Date, the Company shall pay to the Holder, in cash, as liquidated damages and not as a penalty, for each $1,000 of principal amount being converted, $10 per Trading Day (increasing to $20 per Trading Day on the seventh (7^th) Trading Day after such liquidated damages begin to accrue) for each Trading Day after such fourth (4^th) Trading Day until such certificates are delivered. Nothing herein shall limit a Xxxxxx’s right to pursue actual damages or declare an Event of Default pursuant to Section 8 hereof for the Company’s failure to deliver Conversion Shares within the period specified herein and the Holder shall have the right to pursue all remedies available to it hereunder, at law or in equity including, without limitation, a decree of specific performance and/or injunctive relief. The exercise of any such rights shall not prohibit the Holder from seeking to enforce damages pursuant to any other Section hereof or under applicable law.

iv. Compensation for Buy-In on Failure to Timely Deliver Certificates Upon Conversion. In addition to any other rights available to the Holder, if the Company is obligated to and fails for any reason to deliver to the Holder such certificate or certificates by the Share Delivery Date pursuant to Section 4(d)(ii), and if after such Share Delivery Date the Holder is required by its brokerage firm to purchase (in an open market transaction or otherwise), or the Holder’s brokerage firm otherwise purchases, shares of Common Stock to deliver in satisfaction of a sale by the Holder of the Conversion Shares which the Holder was entitled to receive upon the conversion relating to such Share Delivery Date (a “Buy-In”), then the Company shall (A) pay in cash to the Holder (in addition to any other remedies available to or elected by the Holder) the amount by which (x) the Holder’s total purchase price (including any brokerage commissions) for the Common Stock so purchased exceeds (y) the product of (1) the aggregate number of shares of Common Stock that the Holder was entitled to receive from the conversion at issue multiplied by (2) the actual sale price at which the sell order giving rise to such purchase obligation was executed (including any brokerage commissions) and (B) at the option of the Holder, either reissue (if surrendered) this Debenture in a principal amount equal to the principal amount of the attempted conversion or deliver to the Holder the number of shares of Common Stock that would have been issued if the Company had timely complied with its delivery requirements under Section 4(d)(ii). For example, if the Holder purchases Common Stock having a total purchase price of $11,000 to cover a Buy-In with respect to an attempted conversion of this Debenture with respect to which the actual sale price of the Conversion Shares (including any brokerage commissions) giving rise to such purchase obligation was a total of $10,000 under clause (A) of the immediately preceding sentence, the Company shall be required to pay the Holder $1,000. The Holder shall provide the Company written notice indicating the amounts payable to the Holder in respect of the Buy-In and, upon request of the Company, evidence of the amount of such loss. Nothing herein shall limit a Holder’s right to pursue any other remedies available to it hereunder, at law or in equity including, without limitation, a decree of specific performance and/or injunctive relief with respect to the Company’s failure to timely deliver certificates representing shares of Common Stock upon conversion of this Debenture as required pursuant to the terms hereof.

v. Reservation of Shares Issuable Upon Conversion. The Company covenants that it will at all times reserve and keep available out of its authorized and unissued shares of Common Stock for the sole purpose of issuance upon conversion of this Debenture and payment of interest on this Debenture, each as herein provided, free from preemptive rights or any other actual contingent purchase rights of Persons other than the Holder (and the other holders of the Debentures), not less than such aggregate number of shares of the Common Stock as shall (subject to the terms and conditions set forth in the Purchase Agreement) be issuable (taking into account the adjustments and restrictions of Section 5) upon the conversion of the outstanding principal amount of this Debenture and payment of interest hereunder. The Company covenants that all shares of Common Stock that shall be so issuable shall, upon issue, be duly authorized, validly issued, fully paid and nonassessable.

vi. Fractional Shares. No fractional shares or scrip representing fractional shares shall be issued upon the conversion of this Debenture. As to any fraction of a share which Holder would otherwise be entitled to purchase upon such conversion, the Company shall at its election, either pay a cash adjustment in respect of such final fraction in an amount equal to such fraction multiplied by the Conversion Price or round up to the next whole share.

vii. Transfer Taxes. The issuance of certificates for Conversion Shares on conversion of this Debenture shall be made without charge to the Holder hereof for any documentary stamp or similar taxes that may be payable in respect of the issue or delivery of such certificates, provided that, the Company shall not be required to pay any tax that may be payable in respect of any transfer involved in the issuance and delivery of any such certificate upon conversion in a name other than that of the Holder of this Debenture so converted and the Company shall not be required to issue or deliver such certificates unless or until the person or persons requesting the issuance thereof shall have paid to the Company the amount of such tax or shall have established to the satisfaction of the Company that such tax has been paid.

Section 5. Certain Adjustments.

a) Stock Dividends and Stock Splits. If the Company, at any time while this Debenture is outstanding: (i) pays a stock dividend or otherwise makes a distribution or distributions payable in shares of Common Stock on shares of Common Stock or any Common Stock Equivalents (which, for avoidance of doubt, shall not include any shares of Common Stock issued by the Company upon conversion of, or payment of interest on, the Debentures), (ii) subdivides outstanding shares of Common Stock into a larger number of shares, (iii) combines (including by way of a reverse stock split) outstanding shares of Common Stock into a smaller number of shares or (iv) issues, in the event of a reclassification of shares of the Common Stock, any shares of capital stock of the Company, then the Conversion Price shall be multiplied by a fraction of which the numerator shall be the number of shares of Common Stock (excluding any treasury shares of the Company) outstanding immediately before such event and of which the denominator shall be the number of shares of Common Stock outstanding immediately after such event. Any adjustment made pursuant to this Section shall become effective immediately after the record date for the determination of shareholders entitled to receive such dividend or distribution and shall become effective immediately after the effective date in the case of a subdivision, combination or re-classification.

b) Fundamental Transaction. If, at any time while this Debenture is outstanding, (i) the Company effects any merger or consolidation of the Company with or into another Person, (ii) the Company effects any sale of all or substantially all of its assets in one transaction or a series of related transactions, (iii) any tender offer or exchange offer (whether by the Company or another Person) is completed pursuant to which holders of Common Stock are permitted to tender or exchange their shares for other securities, cash or property, or (iv) the Company effects any reclassification of the Common Stock or any compulsory share exchange pursuant to which, with respect to any of the foregoing, the Common Stock is effectively converted into or exchanged for other securities, cash or property (in any such case, a “Fundamental Transaction”), then, upon any subsequent conversion of this Debenture, the Holder shall have the right to receive, for each Conversion Share that would have been issuable upon such conversion immediately prior to the occurrence of such Fundamental Transaction, the same kind and amount of securities, cash or property as it would have been entitled to receive upon the occurrence of such Fundamental Transaction if it had been, immediately prior to such Fundamental Transaction, the holder of 1 share of Common Stock (the “Alternate Consideration”). For purposes of any such conversion, the determination of the Conversion Price shall be appropriately adjusted to apply to such Alternate Consideration based on the amount of Alternate Consideration issuable in respect of 1 share of Common Stock in such Fundamental Transaction, and the Company shall apportion the Conversion Price among the Alternate Consideration in a reasonable manner reflecting the relative value of any different components of the Alternate Consideration. If holders of Common Stock are given any choice as to the securities, cash or property to be received in a Fundamental Transaction, then the Holder shall be given the same choice as to the Alternate Consideration it receives upon any conversion of this Debenture following such Fundamental Transaction. To the extent necessary to effectuate the foregoing provisions, any successor to the Company or surviving entity in such Fundamental Transaction shall issue to the Holder a new debenture consistent with the foregoing provisions and evidencing the Holder’s right to convert such debenture into Alternate Consideration. The terms of any agreement pursuant to which a Fundamental Transaction is effected shall include terms requiring any such successor or surviving entity to comply with the provisions of this Section 5(b) and insuring that this Debenture (or any such replacement security) will be similarly adjusted upon any subsequent transaction analogous to a Fundamental Transaction.

c) Calculations. All calculations under this Section 5 shall be made to the nearest cent or the nearest 1/100th of a share, as the case may be. For purposes of this Section 5, the number of shares of Common Stock deemed to be issued and outstanding as of a given date shall be the sum of the number of shares of Common Stock (excluding any treasury shares of the Company) issued and outstanding.

d) Notice to the Holder.

i. Adjustment to Conversion Price. Whenever the Conversion Price is adjusted pursuant to any provision of this Section 5, the Company shall promptly deliver to each Holder a notice setting forth the Conversion Price after such adjustment and setting forth a brief statement of the facts requiring such adjustment.

ii. Notice to Allow Conversion by Xxxxxx. If (A) the Company shall declare a dividend (or any other distribution in whatever form) on the Common Stock, (B) the Company shall declare a special nonrecurring cash dividend on or a redemption of the Common Stock, (C) the Company shall authorize the granting to all holders of the Common Stock of rights or warrants to subscribe for or purchase any shares of capital stock of any class or of any rights, (D) the approval of any shareholders of the Company shall be required in connection with any reclassification of the Common Stock, any consolidation or merger to which the Company is a party, any sale or transfer of all or substantially all of the assets of the Company, of any compulsory share exchange whereby the Common Stock is converted into other securities, cash or property or (E) the Company shall authorize the voluntary or involuntary dissolution, liquidation or winding up of the affairs of the Company, then, in each case, the Company shall cause to be filed at each office or agency maintained for the purpose of conversion of this Debenture, and shall cause to be delivered to the Holder at its last address as it shall appear upon the Debenture Register, at least twenty (20) calendar days prior to the applicable record or effective date hereinafter specified, a notice stating (x) the date on which a record is to be taken for the purpose of such dividend, distribution, redemption, rights or warrants, or if a record is not to be taken, the date as of which the holders of the Common Stock of record to be entitled to such dividend, distributions, redemption, rights or warrants are to be determined or (y) the date on which such reclassification, consolidation, merger, sale, transfer or share exchange is expected to become effective or close, and the date as of which it is expected that holders of the Common Stock of record shall be entitled to exchange their shares of the Common Stock for securities, cash or other property deliverable upon such reclassification, consolidation, merger, sale, transfer or share exchange, provided that the failure to deliver such notice or any defect therein or in the delivery thereof shall not affect the validity of the corporate action required to be specified in such notice. The Holder is entitled to convert this Debenture during the 20-day period commencing on the date of such notice through the effective date of the event triggering such notice.

Section 6. Intentionally Omitted.

Section 7. Negative Covenants. As long as any portion of this Debenture remains outstanding, unless the holders of at least 51% in principal amount of the then outstanding Debentures shall have otherwise given prior written consent, the Company shall not, and shall not permit any of its subsidiaries (whether or not a Subsidiary on the Original Issue Date) to, directly or indirectly:

a) other than Permitted Indebtedness, enter into, create, incur, assume, guarantee or suffer to exist any indebtedness for borrowed money of any kind, including, but not limited to, a guarantee, on or with respect to any of its property or assets now owned or hereafter acquired or any interest therein or any income or profits therefrom;

b) other than Permitted Liens, enter into, create, incur, assume or suffer to exist any Liens of any kind, on or with respect to any of its property or assets now owned or hereafter acquired or any interest therein or any income or profits therefrom;

c) amend its charter documents, including, without limitation, its amended and restated articles of incorporation, as amended and restated bylaws, in any manner that materially and adversely affects any rights of the Holder;

d) repay, repurchase or offer to repay, repurchase or otherwise acquire more than a de minimis number of shares of its Common Stock or Common Stock Equivalents other than as to (i) the Conversion Shares or Warrant Shares as permitted or required under the Transaction Documents and (ii) repurchases of Common Stock or Common Stock Equivalents of departing officers and directors of the Company, provided that such repurchases shall not exceed an aggregate of $100,000 for all officers and directors during the term of this Debenture;

e) repay, repurchase or offer to repay, repurchase or otherwise acquire any Indebtedness, other than the Debentures or prior issued Debentures if on a pro-rata basis, and other than regularly scheduled principal and interest payments as such terms are in effect as of the Original Issue Date, provided that such payments shall not be permitted if, at such time, or after giving effect to such payment, any Event of Default exists and is continuing or occurs and is continuing;

f) pay cash dividends or distributions on any equity securities of the Company;

g) enter into any transaction with any Affiliate of the Company which would be required to be disclosed in any public filing with the Commission, unless such transaction is made on an arm’s-length basis and expressly approved by a majority of the disinterested directors of the Company (even if less than a quorum otherwise required for board approval); or

h) enter into any agreement with respect to any of the foregoing.

Section 8. Events of Default.

a) “Event of Default” means, wherever used herein, any of the following events (whatever the reason for such event and whether such event shall be voluntary or involuntary or effected by operation of law or pursuant to any judgment, decree or order of any court, or any order, rule or regulation of any administrative or governmental body):

i. any default in the payment of (A) the principal amount of this Debenture or (B) interest, liquidated damages and other amounts owing to a Holder on any Debenture, as and when the same shall become due and payable (whether on a Conversion Date or the Maturity Date or by acceleration or otherwise) which default, solely in the case of an interest payment or other default under clause (B) above, is not cured within 5 Trading Days;

ii. the Company shall fail to observe or perform any other covenant or agreement contained in the Debentures (other than a breach by the Company of its obligations to deliver shares of Common Stock to the Holder upon conversion, which breach is addressed in clause (xi) below) which failure is not cured, if possible to cure, within the earlier to occur of (A) 10 Trading Days after notice of such failure sent by the Holder or by any other Holder to the Company and (B) 15 Trading Days after the Company has become or should have become aware of such failure;

iii. a material default or Event of Default (subject to any grace or cure period provided in the applicable agreement, document or instrument) shall occur under (A) any of the Transaction Documents or (B) any other material agreement, lease, document or instrument to which the Company or any Subsidiary is obligated (and not covered by clause (vi) below) the result of which would reasonably be expected to have a material adverse effect on the operating results and financial condition of the Company;

iv. any representation or warranty made in this Debenture, any other Transaction Documents, any written statement pursuant hereto or thereto or any other report, financial statement or certificate made or delivered to the Holder or any other Holder shall be untrue or incorrect in any material respect as of the date when made or deemed made;

v. the Company or any Significant Subsidiary (as such term is defined in Rule 1-02(w) of Regulation S-X) shall be subject to a Bankruptcy Event;

vi. the Company or any Subsidiary shall default on any of its obligations under any mortgage, credit agreement or other facility, indenture agreement, factoring agreement or other instrument under which there may be issued, or by which there may be secured or evidenced, any indebtedness for borrowed money or money due under any long term leasing or factoring arrangement that (a) involves an obligation greater than $150,000, whether such indebtedness now exists or shall hereafter be created, and (b) results in such indebtedness becoming or being declared due and payable prior to the date on which it would otherwise become due and payable;

vii. the Common Stock shall not be eligible for listing or quotation for trading on a Trading Market and shall not be eligible to resume listing or quotation for trading thereon within seven Trading Days;

viii. the Company shall be a party to any Change of Control Transaction or Fundamental Transaction or shall agree to sell or dispose of all or in excess of 40% of its assets in one transaction or a series of related transactions (whether or not such sale would constitute a Change of Control Transaction);

ix. the Company shall fail for any reason to deliver certificates to a Holder prior to the fifteenth Trading Day after a Conversion Date pursuant to Section 4(d) or the Company shall provide at any time notice to the Holder, including by way of public announcement, of the Company’s intention to not honor requests for conversions of any Debentures in accordance with the terms hereof; or

x. any monetary judgment, writ or similar final process shall be entered or filed against the Company, any subsidiary or any of their respective property or other assets for more than $100,000, and such judgment, writ or similar final process shall remain unvacated, unbonded or unstayed for a period of 45 calendar days.

b) Remedies Upon Event of Default. If any Event of Default occurs, the outstanding principal amount of this Debenture, plus accrued but unpaid interest, liquidated damages and other amounts owing in respect thereof through the date of acceleration, shall become, at the election of Holders of twenty-five percent (25%) of the outstanding aggregate principal amount of Debentures, immediately due and payable in cash at the Mandatory Default Amount, except in the case of an Event of Default pursuant to Section 8(a)(i)(A), which amounts shall become immediately due and payable in cash at the Mandatory Default Amount at the election of the Holder. Commencing 5 days after the occurrence of and during the continuance of any Event of Default that results in the eventual acceleration of this Debenture, the interest rate on this Debenture shall accrue at an interest rate equal to the lesser of 18% per annum or the maximum rate permitted under applicable law. Upon the payment in full of the Mandatory Default Amount, the Holder shall promptly surrender this Debenture to or as directed by the Company. In connection with such acceleration described herein, the Holder need not provide, and the Company hereby waives, any presentment, demand, protest or other notice of any kind, and the Holder may immediately and without expiration of any grace period enforce any and all of its rights and remedies hereunder and all other remedies available to it under applicable law. Such acceleration may be rescinded and annulled by the election of Holders of twenty-five percent (25%) of the outstanding aggregate principal amount of Debentures (or by the election of the Holder in the case of an Event of Default pursuant to Section 8(a)(i)(A)) at any time prior to payment hereunder and the Holder shall have all rights as a holder of the Debenture until such time, if any, as the Holder receives full payment pursuant to this Section 8(b). No such rescission or annulment shall affect any subsequent Event of Default or impair any right consequent thereon.

Section 9. Miscellaneous.

a) Notices. Any and all notices or other communications or deliveries to be provided by the Holder hereunder, including, without limitation, any Notice of Conversion, shall be in writing and delivered personally, by facsimile, by electronic communication or sent by a nationally recognized overnight courier service, addressed to the Company, at the address set forth above, or such other facsimile number or address as the Company may specify for such purpose by notice to the Holder delivered in accordance with this Section 9(a). Any and all notices or other communications or deliveries to be provided by the Company hereunder shall be in writing and delivered personally, by facsimile, by electronic communication or sent by a nationally recognized overnight courier service addressed to each Holder at the facsimile number or address of the Holder appearing on the books of the Company, or if no such facsimile number or address appears, at the principal place of business of the Holder. Any notice or other communication or deliveries hereunder shall be deemed given and effective on the earliest of (i) the date of transmission, if such notice or communication is delivered via facsimile or electronic communication prior to 5:30 p.m. (New York City time), (ii) the date immediately following the date of transmission, if such notice or communication is delivered via facsimile or electronic communication between 5:30 p.m. (New York City time) and 11:59 p.m. (New York City time) on any date, (iii) the second Business Day following the date of mailing, if sent by nationally recognized overnight courier service or (iv) upon actual receipt by the party to whom such notice is required to be given.

b) Absolute Obligation. Except as expressly provided herein, no provision of this Debenture shall alter or impair the obligation of the Company, which is absolute and unconditional, to pay the principal of, liquidated damages and accrued interest, as applicable, on this Debenture at the time, place, and rate, and in the coin or currency, herein prescribed. This Debenture is a direct debt obligation of the Company. This Debenture ranks pari passu with all other Debentures now or hereafter issued under the terms set forth herein.

c) Lost or Mutilated Debenture. If this Debenture shall be mutilated, lost, stolen or destroyed, the Company shall execute and deliver, in exchange and substitution for and upon cancellation of a mutilated Debenture, or in lieu of or in substitution for a lost, stolen or destroyed Debenture, a new Debenture for the principal amount of this Debenture so mutilated, lost, stolen or destroyed, but only upon receipt of evidence of such loss, theft or destruction of such Debenture, and of the ownership hereof, reasonably satisfactory to the Company.

d) Governing Law. All questions concerning the construction, validity, enforcement and interpretation of this Debenture shall be governed by and construed and enforced in accordance with the internal laws of the State of New York, without regard to the principles of conflict of laws thereof. Each party agrees that all legal proceedings concerning the interpretation, enforcement and defense of the transactions contemplated by any of the Transaction Documents (whether brought against a party hereto or its respective Affiliates, directors, officers, shareholders, employees or agents) shall be commenced in the state and federal courts sitting in the City of New York, Borough of Manhattan (the “New York Courts”). Each party hereto hereby irrevocably submits to the exclusive jurisdiction of the New York Courts for the adjudication of any dispute hereunder or in connection herewith or with any transaction contemplated hereby or discussed herein (including with respect to the enforcement of any of the Transaction Documents), and hereby irrevocably waives, and agrees not to assert in any suit, action or proceeding, any claim that it is not personally subject to the jurisdiction of such New York Courts, or such New York Courts are improper or inconvenient venue for such proceeding. Each party hereby irrevocably waives personal service of process and consents to process being served in any such suit, action or proceeding by mailing a copy thereof via registered or certified mail or overnight delivery (with evidence of delivery) to such party at the address in effect for notices to it under this Debenture and agrees that such service shall constitute good and sufficient service of process and notice thereof. Nothing contained herein shall be deemed to limit in any way any right to serve process in any other manner permitted by applicable law. Each party hereto hereby irrevocably waives, to the fullest extent permitted by applicable law, any and all right to trial by jury in any legal proceeding arising out of or relating to this Debenture or the transactions contemplated hereby. If either party shall commence an action or proceeding to enforce any provisions of this Debenture, then the prevailing party in such action or proceeding shall be reimbursed by the other party for its attorneys fees and other costs and expenses incurred in the investigation, preparation and prosecution of such action or proceeding.

e) Waiver. Any waiver by the Company or the Holder of a breach of any provision of this Debenture shall not operate as or be construed to be a waiver of any other breach of such provision or of any breach of any other provision of this Debenture. The failure of the Company or the Holder to insist upon strict adherence to any term of this Debenture on one or more occasions shall not be considered a waiver or deprive that party of the right thereafter to insist upon strict adherence to that term or any other term of this Debenture. Any waiver by the Company or the Holder must be in writing.

f) Severability. If any provision of this Debenture is invalid, illegal or unenforceable, the balance of this Debenture shall remain in effect, and if any provision is inapplicable to any Person or circumstance, it shall nevertheless remain applicable to all other Persons and circumstances. If it shall be found that any interest or other amount deemed interest due hereunder violates the applicable law governing usury, the applicable rate of interest due hereunder shall automatically be lowered to equal the maximum rate of interest permitted under applicable law. The Company covenants (to the extent that it may lawfully do so) that it shall not at any time insist upon, plead, or in any manner whatsoever claim or take the benefit or advantage of, any stay, extension or usury law or other law which would prohibit or forgive the Company from paying all or any portion of the principal of or interest on this Debenture as contemplated herein, wherever enacted, now or at any time hereafter in force, or which may affect the covenants or the performance of this indenture, and the Company (to the extent it may lawfully do so) hereby expressly waives all benefits or advantage of any such law, and covenants that it will not, by resort to any such law, hinder, delay or impede the execution of any power herein granted to the Holder, but will suffer and permit the execution of every such as though no such law has been enacted.

g) Next Business Day. Whenever any payment or other obligation hereunder shall be due on a day other than a Business Day, such payment shall be made on the next succeeding Business Day.

h) Headings. The headings contained herein are for convenience only, do not constitute a part of this Debenture and shall not be deemed to limit or affect any of the provisions hereof.

i) Assumption. Any successor to the Company or any surviving entity in a Fundamental Transaction shall (i) assume, prior to such Fundamental Transaction, all of the obligations of the Company under this Debenture and the other Transaction Documents pursuant to written agreements in form and substance satisfactory to the Holder (such approval not to be unreasonably withheld or delayed) and (ii) issue to the Holder a new debenture of such successor entity evidenced by a written instrument substantially similar in form and substance to this Debenture, including, without limitation, having a principal amount and interest rate equal to the principal amount and the interest rate of this Debenture and having similar ranking to this Debenture, which shall be satisfactory to the Holder (any such approval not to be unreasonably withheld or delayed). The provisions of this Section 9(i) shall apply similarly and equally to successive Fundamental Transactions and shall be applied without regard to any limitations of this Debenture.

j) Existence of Class. Holder acknowledges and agrees by acceptance hereof that such Holder has been offered and sold this Debenture pursuant to that certain subscription agreement dated [_____], 2012 (the “Subscription Agreement”) and that all such Holders of Debentures offered and sold pursuant to the Subscription Agreement shall be part of and act as a class (the “Convertible Debenture Holders”) for all purposes, including but not limited to any amendments, waivers or defaults. Any such action shall require the affirmative consent of Holders of a twenty-five percent (25%) in outstanding aggregate principal amount of Debentures sold to the Convertible Debenture Holders (except in the case of an Event of Default pursuant to Section 8(a)(i)(A)). All payments made in connection with any Event of Default (except in the case of an Event of Default pursuant to Section 8(a)(i)(A)) or any dissolution, winding up or other event of liquidation with respect to the Company shall be made pro rata to all Holders in proportion to such Holder’s percentage interest of the aggregate principal amount of Debentures sold to the Convertible Debenture Holders.

k) Subscription Agreement. In connection with the issuance of this Debenture, the Holder has executed a Subscription Agreement and hereby acknowledges and agrees that the representations and warranties made by the Holder in such Subscription Agreement shall be incorporated by reference into this Debenture as if fully set forth herein.

*********************

(Signature Pages Follow)

IN WITNESS WHEREOF, the Company has caused this Debenture to be duly executed by a duly authorized officer as of the date first above indicated.

	Spectrascience, Inc.
	By:__________________________________________ Name: Title: Facsimile No. for delivery of Notices: _______________

ANNEX A

NOTICE OF CONVERSION

The undersigned hereby elects to convert principal under the 5% Original Issue Discount Convertible Debenture due ______ __, 2013 of Spectrascience, Inc., a Minnesota corporation (the “Company”), into shares of common stock (the “Common Stock”), of the Company according to the conditions hereof, as of the date written below. If shares of Common Stock are to be issued in the name of a person other than the undersigned, the undersigned will pay all transfer taxes payable with respect thereto and is delivering herewith such certificates and opinions as reasonably requested by the Company in accordance therewith. No fee will be charged to the holder for any conversion, except for such transfer taxes, if any.

By the delivery of this Notice of Conversion the undersigned represents and warrants to the Company that its ownership of the Common Stock does not exceed the amounts specified under Section 4 of this Debenture, as determined in accordance with Section 13(d) of the Exchange Act.

The undersigned agrees to comply with the prospectus delivery requirements under the applicable securities laws in connection with any transfer of the aforesaid shares of Common Stock.

Conversion calculations:

	Date to Effect Conversion:

	Principal Amount of Debenture to be Converted:

	Payment of Interest in Common Stock __ yes __ no
	If yes, $_____ of
	Interest Accrued.
	Number of Conversion Shares payable on Principal or Interest that would exceed the limits set forth in Section 4(c) of the Note:

	Number of shares of Common Stock to be issued:


	Signature:

	Name:

	Address for Delivery of Common Stock Certificates

Schedule 1

CONVERSION SCHEDULE

The 5% Original Issue Discount Unsecured Convertible Debenture due on ____________, 2013 in the original principal amount of $____________ is issued by SpectraScience, Inc., a Minnesota corporation. This Conversion Schedule reflects conversions made under Section 4 of the above referenced Debenture.

Dated:

Date of Conversion

(or for first entry, Original Issue Date)

Amount of Conversion

Aggregate Principal Amount Remaining Subsequent to Conversion

(or original Principal Amount)

Company Attest