title: Isolation of circulating megakaryocytes in man.
abstract: Recovery of the small numbers of megakaryocytes (MKs) known to be present in normal blood is difficult because of their low frequency. Isolation of circulating MKs was achieved using a modified filtration system in which untreated blood was passed through 5 microns polycarbonate membranes. MKs were retained while most other blood cells passed through the membranes. Four groups of MKs were identified in May Grünwald-Giemsa stained filters of blood from peripheral, central and umbilical veins and umbilical arteries. Type 1 MKs were nuclei with no visible cytoplasm. Types 2, 3 and 4 were nuclei with increasing amounts of cytoplasm. Type 4 MKs, possessing copious cytoplasm, were rarely isolated from peripheral venous blood but were more regularly encountered in central venous and cord blood. Filtration of whole blood through polycarbonate membranes is a useful technique for the isolation of circulating MKs, which are a normal physiological occurrence. Their presence is consistent with the production of platelets in the placenta during intra-uterine life, and subsequently in the pulmonary circulation.
authors.affiliation: Department of Medical Physics, University of Sheffield, UK.
authors.forename: M J
authors.initials: MJ
authors.lastname: Woods
authors.forename: C R
authors.initials: CR
authors.lastname: Landon
authors.forename: B E
authors.initials: BE
authors.lastname: Wagner
authors.forename: M
authors.initials: M
authors.lastname: Greaves
authors.forename: E A
authors.initials: EA
authors.lastname: Trowbridge
mesh_terms: D006440:Hemofiltration / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D008533:Megakaryocytes / Q000166:cytology / Q000648:ultrastructure