Re: Asset Purchase Agreement

Exhibit 2.6

NOVITRON INTERNATIONAL, INC.

Xxx Xxxxxxx Xxxxxx, Xxxxx 000
Xxxxxx, XX 00000

March 31, 0000

XXXX XXXXXXXXXXXXXXX, INC.

ELAN DIAGOSTICS, INC.

c/o Elan Pharmaceuticals, Inc.
000 Xxxxxxx Xxxxxxxxx
Xxxxx Xxx Xxxxxxxxx, XX 00000

Re: Asset Purchase Agreement

Ladies and Gentlemen:

We refer you to the Asset Purchase Agreement, dated as of December 9, 2002 (the "Asset Purchase Agreement"), by and among Elan Pharmaceuticals, Inc., a Delaware corporation, Elan Diagnostics, Inc., a Delaware corporation, and Novitron International, Inc., a Delaware corporation.

This letter confirms our agreement to extend the date set forth in clause (ii) of Section 10.1 of the Asset Purchase Agreement from April 8, 2003 to May 1, 2003.

Please confirm that the foregoing accurately sets forth our agreement by executing a copy hereof in the space provided below and returning it to the undersigned.

Very truly yours,

NOVITRON INTERNATIONAL, INC.

By: /s/ Xxxxxx X. Xxxxx
Xxxxxx X. Xxxxx
Chairman of the Board and
Chief Executive Officer

Acknowledged and agreed
as of the date set forth above:

ELAN PHARMACEUTICALS, INC.

By: /s/ Xxxxx X. Xxxxxx
Xxxxx X. Xxxxxx
Vice President and Chief Financial Officer

ELAN DIAGNOSTICS, INC.

By: /s/ Xxxxxx X. Xxxxxx
Xxxxxx X. Xxxxxx
Assistant Treasurer