Positive Selectable Markers for Use with Mammalian Cells in Culture

As more complicated gene expression studies are necessary, the need for multiple positive selection schemes becomes critical. Numerous selectable markers have been described over the last 25 years. A hallmark of the most generally useful markers is easy selection in a wide number of cell types. This paper briefly reviews the spectrum of available selectable markers and describes some of the applications that have been found for these genes, particularly with respect to retrovirus-mediated gene transfer. This review summarizes the positive selectable markers available to mammalian cell biologists and molecular biologists. Some of the applications found for these markers, particularly with respect to retroviral vectors, are discussed.