At the beginning of 2000, the Diagnostics business unit began efforts to refocus on niche opportunities, with a three-year plan to restore its contribution toward the overall Company's targets to achieve sales and profit growth of 10%. Results in Diagnostics through 2001 have not met expectations. The EIA products, which are supplied by third party vendors and marketed by the Diagnostics business unit, represent less than 10% of that unit's sales and roughly 0.5% of total sales for Sigma-Aldrich. This product line had a modest adverse impact on overall Sigma-Aldrich profitability.

Management does not believe that the proposed EIA transaction in and of itself should affect the price of Sigma-Aldrich stock.

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 chemical manufacturing. We have customers in life science companies, university and government institutions, hospitals and in industry. Sigma-Aldrich operates in 33 countries and has 6,500 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. Cautionary Statement: This release contains forward-looking statements relating to future performance, goals, strategic actions and initiatives and similar intentions and beliefs, and other statements regarding the Company's expectations, goals, beliefs, intentions and the like regarding future sales, earnings, return on equity and other matters. These statements involve assumptions regarding Company operations, investments and acquisitions and conditions in the markets the Company serves. Although the Company believes its expectations are based on reasonable assumptions, such statements are subject to risks and uncertainties, including, among others, certain economic, political and technological factors. Actual results could differ materially from those stated or implied in this news release, due to, but not limited to, such factors as changes in pricing and the competitive environment, other changes in the business environment in which the Company operates, changes in research funding, uncertainties surrounding government healthcare reform, government regulations applicable to the business, the impact of fluctuations in interest rates and foreign currency exchange rates and the effectiveness of the Company's further implementation of its global software systems. The Company does not undertake any obligation to update these forward-looking statements.

For more information about Sigma-Aldrich, please visit our award-winning web site at www.sigma-aldrich.com