Detection of surface differences between closely related cell populations by partitioning. Cultured K-562 cell sublines.

The K-562 cell line is a culture of human leukemia stem cells originally derived from a patient with chronic myelogenous leukemia in blast crisis. We have applied a sensitive method capable of detecting subtle differences in charge-associated and noncharge-related cell surface properties between closely related cell populations to K-562 cells from different sources and having different histories. The method consists of isotopically labeling aliquots of each of two cell populations to be compared with 51Cr-chromate and mixing the labeled cells with an excess of unlabeled cells with which they are to be compared.

Fractionation of K-562 cells on the basis of their surface properties by partitioning in two-polymer aqueous-phase systems.

The K-562 cell line is a culture of human leukemia stem cells originally derived from a patient with chronic myelogenous leukemia in blast crisis. We have subjected such cells, in the log phase of growth, to countercurrent distribution in a charge-sensitive dextran-polyethylene glycol aqueous-phase system, a method that fractionates cells on the basis of subtle differences in their surface properties, and found that: (1) The cell population is heterogeneous since it is composed of cells with different partition ratios. (2) There is a correlation between increasing cell partition ratios and increasing cell electrophoretic mobilities.

The partitioning behavior of K-562 cells associated with different stages of culture growth.

Partitioning behavior of cells in dextran-poly(ethylene glycol) aqueous phase systems is a sensitive reflection of the cells' surface properties. A decrease in partition ratio, in charge-sensitive phases, of a variety of cell lines as a function of culture growth has been reported by a number of investigators. The basis for this phenomenon remains unclear.