New 24 Well Transwell inserts aseptically precoated with Cultrex® Basement Membrane Extract (BME) by Trevigen, Inc. are now available with 8.0 µm pore polycarbonate membranes. Cultrex Basement Membrane Extract is a soluble form of basement membrane purified from Engelbreth-Holm-Swarm (EHS) tumor. The major components of the BME include laminin I, collagen IV, entactin, and heparin sulfate proteoglycan.