Cambridge Isotope Laboratories Inc., an Andover-based company that makes research biochemicals, is leasing 38,500 square feet of space at an office park in Tewksbury as it looks to expand its Massachusetts footprint, said a broker involved in the transaction.

The broker is the commercial real estate firm Cushman & Wakefield. The firm said it represented BPG Properties Ltd. in the transaction. BPG is the landlord of the Highwood Office Park, a three building complex where Cambridge Isotope Laboratories, or CIL, plans to relocate some of its operations.