On October 2, 2009, Sigma-Aldrich announced the appointment of Dr. George M. Church as a Director of the Company effective on that date. Dr. Church (age 55) is a Professor of Genetics at the Harvard Medical School and Director of the Center for Computational Genetics in Cambridge, Massachusetts. Dr. Church will serve as an independent, non-employee Director, and is not expected to be appointed to any standing Board Committee.

There are no arrangements between Dr. Church and any other person pursuant to which Dr. Church was elected to serve as a Director. The Company is not aware of any transaction, proposed transaction or series of either, since January 1, 2008, in which the amount involved exceeds $120,000,in which the Company is or will be a participant and Dr. Church has or will have a direct or indirect material interest.

As a non-employee Director, Dr. Church will receive the same compensation paid to other non-employee Directors of the Company in accordance with the policies and procedures previously approved by the Board for non-employee Directors as disclosed under the caption "Director Compensation and Transactions" in the Company's proxy statement filed with the Securities and Exchange Commission on March 13, 2009.

On October 2, 2009, Sigma-Aldrich issued a press release announcing the appointment of Dr. George M. Church as a Director of the Company effective on that date. A copy of the press release is furnished as Exhibit 99.1 hereto and is incorporated by reference herein. The description of the press release contained herein is qualified in its entirety by the full text of such exhibit.

(d) Exhibits

The following Exhibits are furnished with this Current Report on Form 8-K:

Exhibit
Number                                    Description
99.1         Press Release issued October 2, 2009-SIGMA-ALDRICH ELECTS GEORGE M.
             CHURCH AS DIRECTOR.