title: Fluorescence-activated cell analysis and sorting of viable mammalian cells based on beta-D-galactosidase activity after transduction of Escherichia coli lacZ.
abstract: We demonstrate that individual cells infected with and expressing a recombinant retrovirus carrying the Escherichia coli beta-galactosidase gene (lacZ) can be viably stained, analyzed, sorted, and cloned by fluorescence-activated cell sorting based on the levels of lacZ expressed. To accomplish this we have devised a method to enzymatically generate and maintain fluorescence in live mammalian cells. Accumulation of fluorescent products in cells is linear with time, with a direct correlation of fluorescence to enzymatic activity. This technology for beta-galactosidase detection is more sensitive than other available cytochemical or biochemical methods. We have used this procedure to show that the expression of psi-2-MMuLVSVnlsLacZ in the T-cell lymphoma BW5147 and the B-cell hybridoma SP2/0 is not completely stable and that subclones selected by the fluorescence-activated cell sorter for low lacZ activity demonstrate distinctly lower average expression of LacZ. These findings indicate the utility of beta-galactosidase as a reporter molecule at the single-cell level for studies of gene regulation, including studies of promoter efficacy, enhancer activity, trans-acting factors, and other regulatory elements.
mesh_terms: D000818:Animals; D002460:Cell Line; D002469:Cell Separation / Q000379:methods*; D004926:Escherichia coli; D005434:Flow Cytometry / Q000379:methods*; D005696:Galactosidases / Q000032:analysis*; D005786:Gene Expression Regulation; D005798:Genes, Bacterial; D051379:Mice; D014161:Transduction, Genetic; D001616:beta-Galactosidase / Q000032:analysis* / Q000235:genetics
chemical_list: D005696:Galactosidases; D001616:beta-Galactosidase