On Assignment Inc. (NYSE: ASGN), the third-largest provider of clinical/scientific staffing, acquired Stratacuity Staffing Partners Inc., a smaller provider of clinical/scientific staffing that ranked on this year’s list of fastest-growing US staffing firms.

Stratacuity is based in Portsmouth, NH, and serves clients in the Boston area. It was founded in 2001 by Robert Patten and Patrick Marshall. It posted total revenue of $16 million in 2016.

“This acquisition enables On Assignment to build upon its presence in its Life Sciences staffing vertical and provides us with a great opportunity to strengthen our Clinical Research offerings to our clients making us one of the largest providers of scientific and clinical staffing solutions,” according to Calabasas, Calif.-based On Assignment.

The transaction closed Aug. 8 and terms were not disclosed. Senior operating management will continue to run the business.