Isolation of human myoblasts with the fluorescence-activated cell sorter.

We have established procedures for the rapid and efficient purification of human myoblasts using the fluorescence-activated cell sorter. Our approach capitalizes on the specific reaction of monoclonal antibody 5.1H11 with a human muscle cell surface antigen. For each of the five samples analyzed, an enrichment of myoblasts to greater than 99% of the cell population was immediately achieved. Following 3 to 4 weeks of additional growth in vitro, sorted myoblast cultures remained 97% pure. Differentiation of the sorted myoblast cultures, assessed by creatine kinase activity and isozyme content, was comparable to that of pure myoblast cultures obtained by cloning, and was significantly greater than that of mixed fibroblast and myoblast cultures. An average of 10(4) viable myoblasts can be obtained per 0.1 g tissue, each with the potential to undergo approximately 40 cell divisions. Accordingly, if only two-thirds of this proliferative capacity is utilized, the potential yield approximates 10(12) myoblasts, equivalent to 1 kg of cells. Human myogenesis in vitro is no longer limited by cell number and is now amenable to molecular and biochemical analysis on a large scale.+