Long-term maintenance of primary myogenic cultures on a reconstituted basement membrane.

We describe a simple technique for maintaining highly contractile long-term chicken myogenic cultures on Matrigel, a gel composed of basement membrane components extracted from the Engelbreth-Holm-Swarm mouse tumor. Cultures grown on Matrigel consist of three-dimensional multilayers of cylindrical, contracting myotubes which endure for at least 60 d without myotube detachment. A Matrigel substrate increases the initial plating efficiency but does not effect cell proliferation. Large-scale differentiation in cultures maintained on Matrigel is delayed by 1 to 2 d, compared to cultures grown on gelatin-coated dishes. Long-term maintenance on Matrigel also results in increased expression of the neonatal and adult fast myosin heavy chain isoforms. Culturing of cells on a Matrigel substrate could thus facilitate the study of later events of in vitro myogenesis.