A universally applicable method of isolating somatic cell hybrids by two-colour flow sorting

A generally applicable technique is described that permits easy identification and isolation of heterokaryons a few hours after fusion. It is based on the labelling of living cells with different fluorochromes, which, at appropriate concentrations do not affect viability or gene expression. Both fluorochromes are relatively stable and do not cross-contaminate unlabelled cells. The technique has a powerful potential in studies on gene regulation in somatic cell hybrids since heterofluorescent hybrids between any type of cells can be isolated directly from large populations of monofluorescent parental cells by using a cell sorter equipped with a single laser. Thus the technique avoids the need for genetically marked parental cells for selection.