BD Living Colors™ pIRES2-DsRed-Express Vector can be used to quickly identify mammalian cells expressing a gene of interest by selecting red fluorescent cells. This vector contains the internal ribosome entry site (IRES) of the encephalomyocarditis virus, which permits both the gene of interest and the DsRed-Express coding region to be translated from a single mRNA. Virtually 100% of red fluorescent cells detected by fluorescence microscopy or flow cytometry will also express the gene of interest. Selected cells or cell populations can be used directly in assays, eliminating any variability due to transfection efficiency from your experiments.