Sartorius has signed an agreement to acquire U.S.-based Essen BioScience Inc., a provider of cell-based assays and instrumentation used for drug discovery and research applications. The transaction, which is subject to customary closing conditions, is expected to close 1Q17.   Sartorius will purchase Essen BioScience from SFW Capital Partners for $320 million in cash. Essen expects to generate revenues of approximately $60 million in 2017, with continued double-digit growth. The company is hea...