Abstract
The effect of various fractions of serum on active epidermal cell migration in vitro has been studied by incubating small explants of normal human skin in the presence of the fractions and determining the extent of migration after 48 h incubation. Serum was fractionated by combining ammonium sulphate precipitation and molecular sieve chromatography using Sephadex G‐200. The components of serum responsible for most, if not all, of the migration promotion activity were localized in the G‐200 third peak (albumin fraction) of the supernatant after precipitation of the serum with ammonium sulphate at 50% saturation.