title: Enumeration of human lymphocyte subsets by monoclonal antibodies and flow cytometry: a comparative study using whole blood or mononuclear cells separated by density gradient centrifugation.
abstract: Enumeration of lymphocyte subpopulations by combined use of flow cytometry and monoclonal antibodies is influenced by the separation method used. T or B lymphocyte antigen frequencies do not differ in samples of whole blood or after separation on Ficoll-Paque or Percoll, but there is a significant increase of Leu+ Leu11+ lymphocytes showing strong natural killer activity at the sample-separation medium interface. At the bottom of the tubes a selective loss of OKT+, Leu7+, Leu11- cells is found; at this level cytotoxicity is very low. Our data suggest that Leu7+ cells could be subdivided into 2 subpopulations differing in reactivity with the monoclonal antibody to Leu11, natural killer activity and density. Differences observed in the percentages of Leu7+, Leu11+ lymphocytes between whole blood and separated cells could be due to an enrichment produced by centrifugation or to the presence in whole blood of a factor interfering with antibody binding.
mesh_terms: D000911:Antibodies, Monoclonal; D001402:B-Lymphocytes; D002469:Cell Separation / Q000379:methods*; D002499:Centrifugation, Density Gradient; D005434:Flow Cytometry; D006801:Humans; D007694:Killer Cells, Natural; D007958:Leukocyte Count / Q000379:methods; D008214:Lymphocytes / Q000145:classification* / Q000276:immunology; D013601:T-Lymphocytes / Q000145:classification
chemical_list: D000911:Antibodies, Monoclonal