3050 Spruce Street, St. Louis, MO 63103 USA
Tel: (314) 898-4645 Fax: (314) 286-8051
April 20, 2012
VIA EDGAR AND FEDERAL EXPRESS
Mr. John Cash
Accounting Branch Chief
Division of Corporation Finance
U.S. Securities and Exchange Commission
100 F Street, NE
Washington, D.C. 20549
RE: Sigma-Aldrich Corporation
Form 10-K for the Fiscal Year Ended December 31, 2011
Filed February 13, 2012
Definitive Proxy Statement on Schedule 14A
Filed March 12, 2012
File No. 0-08135
Dear Mr. Cash:
We received your letter dated April 17, 2012 (the “SEC Letter”). Per the terms of the SEC Letter and our telephone conversation with your colleague, Era Anagnosti, on April 19, 2012, we hereby notify you that we shall submit our response to the SEC Letter on or before May 15, 2012.
Please contact me at (314) 898-4645 if you have any questions.
Sincerely,
/s/ Jan A. Bertsch
Jan A. Bertsch
Executive Vice President and Chief Financial Officer
