Private equity firm SFW Capital Partners has invested in Essen BioScience Inc.

Essen, headquartered in Ann Arbor, Michigan, provides analytical instrumentation, software and other services used in life science research. The company makes IncuCyte Zoom, an imaging system used for cell analysis. Essen's products are used by academic institutions, as well as  major pharmaceutical companies such as Amgen Inc. (Nasdaq: AMGN), AstraZeneca plc (NYSE: AZN), Bristol-Myers Squibb Co. (NYSE: BMY), Genentech, GlaxoSmithKline plc (NYSE: GSK), Merck & Co. (NYSE: MRK) and Pfizer Inc. (NYSE: PFE).

SFW's investment should help Essen develop new products and expand sales and support capabilities.

Rye, New York-based SFW invests in analytical tools and related services companies. In November, the firm invested in Filtec, a company that provides automated inspection systems for the beverage industry. SFW's other investments include Agdata, a data provider to the agriculture sector, and Spectro Scientific, which supplies instrumentation and software for machine-condition monitoring. The firm usually invets $15 million to $75 million per deal. The firm is still investing out of its debut fund, which closed in 2008 with $300 million.