“…AchE is an enzyme which has been shown to be relatively specific for the megakaryocytic lineage in rodents, and can be identified in small cells which are unrecognizable as megakaryocytes by standard morphologic features (Jackson, 1973;Long and Henry, 1979;Long and Williams, 1981). Techniques for the separation and partial isolation of these classes of megakaryocytes have been described (Nakeff and Maat, 1974;Leif et al, 1975; 0 1985 ALAN R. LISS, INC Levine and Fedorko, 1976;Nakeff and Floeh, 1976;Pretlow and Stinson, 1976;Nachman et al, 1977;Sitar et al, 1977;Rabellino et al, 1979;Levine, 1980;Worthington and Nakeff, 1981;Williams et al, 1981;Long et al, 1982;Sitar, 1984). Rabellino et al (1979) found that mature human megakaryocytes are found at the top of discontinuous Percoll gradients at low density (less than 1.050 g/cm3).…”