0001193125-07-137665 Sample Contracts

Form of Warrant] THIS WARRANT AND THE SHARES OF COMMON STOCK ISSUED UPON ITS EXERCISE ARE SUBJECT TO THE RESTRICTIONS ON TRANSFER SET FORTH IN SECTION 4 OF THIS WARRANT

Common Stock Purchase Warrant • June 18th, 2007 • Sontra Medical Corp • Electromedical & electrotherapeutic apparatus • Massachusetts

• Contract Type
  Common Stock Purchase Warrant
• Filed
  June 18th, 2007
• Company
  Sontra Medical Corp
• Industry
  Electromedical & electrotherapeutic apparatus
• Jurisdiction
  Massachusetts

Sontra Medical Corporation, a Minnesota corporation (the “Company”), for value received, hereby certifies that , or its registered assigns (the “Registered Holder”), is entitled, subject to the terms and conditions set forth below, to purchase from the Company, at any time or from time to time on or after the date of issuance and on or before 5:00 p.m. (New York time) on the fifth anniversary hereof, shares of Common Stock, U.S.$0.01 par value per share, of the Company, at a purchase price of U.S.$1.40 per share. The shares purchasable upon exercise of this Warrant, and the purchase price per share, each as adjusted from time to time pursuant to the provisions of this Warrant, are hereinafter referred to as the “Warrant Shares” and the “Purchase Price,” respectively.

Form of Subscription Agreement] SONTRA MEDICAL CORPORATION Subscription Agreement

Subscription Agreement • June 18th, 2007 • Sontra Medical Corp • Electromedical & electrotherapeutic apparatus • Minnesota

• Contract Type
  Subscription Agreement
• Filed
  June 18th, 2007
• Company
  Sontra Medical Corp
• Industry
  Electromedical & electrotherapeutic apparatus
• Jurisdiction
  Minnesota

The undersigned purchaser (the “Purchaser”) hereby offers to purchase the number of units comprised of Common Stock of Sontra Medical Corporation, a Minnesota corporation (the “Company”) and warrants for Common Stock in the Company, set forth on the signature page hereof, (the “Units”). Each Unit shall include one share of Common Stock in the Company and a warrant for the purchase of 30% of one share of Common Stock in the Company. This offer to purchase may, for any reason whatsoever, be revoked by the Purchaser or rejected by the Company prior to acceptance of this offer by the Company. The Units being purchased hereby are part of a private placement offering of up to 3,000,000 shares of Common Stock plus warrants to purchase up to 900,000 shares of Common Stock.