Sigma-Aldrich Corporation Announces 2nd Quarter 2009 Earnings Conference Call

ST. LOUIS, July 13, 2009 (GLOBE NEWSWIRE) -- Sigma-Aldrich Corporation
(Nasdaq:SIAL) will hold its quarterly conference call to discuss second quarter
results on Thursday, July 23, 2009, at 11:00 a.m. Eastern Time (10 a.m. Central
Time).

Date: July 23, 2009
Time: 10:00 AM CT

Toll Free: 888-287-5420
International: 719-785-1764
Passcode: 4329205
Webcast and slide presentation available via internet:
http://investor.sigmaaldrich.com/

Schedule this webcast into MS-Outlook calendar (click open when prompted):
http://apps.shareholder.com/PNWOutlook/t.aspx?m=37520&k=927480E2

A replay of the call will be available from 07/23/09, 2:00 p.m. Central until
07/30/09, 11:59 p.m. Central. For replay, please dial:

Toll Free: 888-203-1112 International: 719-457-0820 Passcode: 4329205

Sigma-Aldrich is a leading Life Science and High Technology company. Its
biochemical and organic chemical products and kits are used in scientific
research, including genomic and proteomic research, biotechnology,
pharmaceutical development and as key components in pharmaceutical, diagnostic
and other high technology manufacturing. The Company has customers in life
science companies, university and government institutions, hospitals, and in
industry. Over one million scientists and technologists use its products.
Sigma-Aldrich operates in 38 countries and has 7,800 employees providing
excellent service worldwide. Sigma-Aldrich is committed to Accelerating Customer
Success through Innovation and Leadership in Life Science, High Technology and
Service. For more information about Sigma-Aldrich, please visit its
award-winning Web site at http://www.sigma-aldrich.com.

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CONTACT: Sigma-Aldrich Corporation
Media:
Carrie Fields
314-286-8015
carrie.fields@sial.com