Distribution of Alkaline Phosphatase Variants in a Heteroploid Strain of Human Cells in Tissue Culture

Abstract

ATTEMPTS to demonstrate possible genetic interactions among mammalian cells grown in tissue culture have been hampered by the lack of suitable markers which may be conveniently detected and scored among large cellular populations. The difficulty in initiating genetic studies with this material is due, in large part, to the considerable biochemical and morphological uniformity which characterizes mammalian cell strains, of whatever origin, established in vitro. Recently, however, it has been shown that there exists striking differences in the alkaline phosphatase activity of a sub-line of HeLa cells as compared with the parent culture¹ and between several human cell strains of different origins^2,3. We describe here a simple technique which permits the detection and isolation of variant clones of human tissue culture cells which lack alkaline phosphatase or which show diminished amounts of the enzyme activity. In addition, we give some preliminary results pertaining to the clonal distribution and properties of some alkaline phosphatase variants which were obtained by use of this technique.