Form of Change of Control Agreement Between Aclara Biosciences

EXHIBIT 10.43


[ACLARA BioSciences, Inc. Letterhead]


[ Date ], 2003

[ Director Name ]

[ Address ] Re: Non-Employee Director Change in Control Agreement

Dear Mr/s. ____________:

ACLARA BioSciences, Inc. (the " Company" ) considers it essential to the best interests of its shareholders to foster the continuous service of the Company' s non-employee directors. In this regard, the Company' s Board of Directors (the " Board" ) has decided to reinforce and encourage the continued attention and dedication of non-employee members of the Board, including yourself, to their duties without the distraction arising from the possibility of a change in control of the Company.

The Company hereby agrees that after this letter agreement (this " Agreement" ) has been fully executed, you shall receive the benefits set forth in this Agreement in the event of a Hostile Takeover (as defined below) or a Change in Control (as defined below).

1. Term of Agreement . This Agreement shall commence on the date hereof and shall continue in effect through December 31, 2003; provided , however , that commencing on January 1, 2004 and on each January 1 thereafter, the term of this Agreement shall automatically be extended for one additional year unless, not later than September 30 of the preceding year, the Company shall have given you notice that it does not wish to extend this Agreement.

2. Change in Control/Hostile Takeover . You shall receive no benefits under this Agreement unless there has been a Change in Control or a Hostile Takeover.


(a) For purposes of this Agreement, a " Change in Control" shall mean (i) an acquisition of any voting securities of the Company (the " Voting Securities" ) by any " person" (as the term " person" is used for purposes of Section 13(d) or Section 14(d) of the Securities Exchange Act of 1934, as amended (the " 1934 Act" )) immediately after which such person has " beneficial ownership" (within the meaning of Rule 13d-3 promulgated under the 1934 Act) (" Beneficial Ownership" ) of 15% or more of the combined voting power of the Company' s then outstanding Voting Securities without the approval of the Board; (ii) a merger or consolidation that results in more than 50% of the combined voting power of the Company' s then outstanding Voting Securities of the Company or its successor changing ownership (whether or not approved by the Boar ...