Sartorius Group AG has acquired instrument maker Essen BioScience Inc. from SFW Capital Partners for $320 million. SFW made an investment in the target in 2014.

Essen, based in Ann Arbor, Michigan and founded in 1996, develops instruments and software for life sciences under the IncuCyte system. IncuCyte monitors real time cellular behavior by gathering images for researchers. The target expects to generate around $60 million in sales in 2017.

Sartorius, located in Goettingen, Germany, is a medical equipment provider. The company concentrates on distributing instruments that go into producing biotech medicines and vaccines as well as biopharmaceutical research. CEO Joachim Kreuzburg says the addition of Essen will expand the company's lab division.

New York-based SFW typically invests between $10 million to and $75 million in equity, concentrating mostly on data analytics and instrument businesses. Some of the PE firm's current investments include: analytics provider BLI-Info Trends, business management software company Day Smart Software and beverage instrument supplier Filtec.

In other instrument-related deals, Harbour Group-backed Onicon acquired sensor produce Greyline Instruments and Windjammer Capital Investors purchased medical test equipment maker Advanced Instruments.