Sigma-Aldrich Corporation 1st Quarter 2008 Earnings Conference Call

ST. LOUIS, April 11 /PRNewswire-FirstCall/ -- Sigma-Aldrich Corporation (Nasdaq: SIAL), will hold its quarterly conference call to discuss first quarter results on Wednesday, April 23, 2008, at 11:00 a.m. Eastern Time (10 a.m. Central Time).

This call is being webcast by Thomson/CCBN and can be accessed at Sigma- Aldrich's Web site at www.sigma-aldrich.com.

The webcast is also being distributed through the Thomson StreetEvents Network to both institutional and individual investors. Individual investors can listen to the call at www.fulldisclosure.com, Thomson/CCBN's individual investor portal, powered by StreetEvents. Institutional investors can access the call via Thomson's password-protected event management site, StreetEvents (www.streetevents.com).

About Sigma-Aldrich: Sigma-Aldrich is a leading Life Science and High Technology company. Our biochemical and organic chemical products and kits are used in scientific and genomic research, biotechnology, pharmaceutical development, the diagnosis of disease and as key components in pharmaceutical and other high technology manufacturing. We have customers in life science companies, university and government institutions, hospitals and in industry. Over one million scientists and technologists use our products. Sigma-Aldrich operates in 36 countries and has over 7,900 employees providing excellent service worldwide. We are committed to the success of our Customers, Employees and Shareholders through leadership in Life Science, High Technology and Service. For more information about Sigma-Aldrich, please visit our award- winning web site at www.sigma-aldrich.com

Media Contact

Debbie Bockius, 314.286.8015

[email protected]

SOURCE Sigma-Aldrich Corporation