The EFLUXX-ID Multidrug Resistance Assay Kit allows for functional detection of all three clinically relevant ABC transporter proteins: MDR1 (p-glycoprotein), MRP1/2, and BCRP. The assay uses a hydrophobic, non-fluorescent compound that readily penetrates the cell membrane, where it is hydrolyzed to a hydrophilic fluorescent dye by intracellular esterases. Unless the EFLUXX-ID dye is pumped out of the cell, the esterase cleaved dye is trapped inside the cell. Thus, cells exhibiting drug resistance will have diminished fluorescence. EFLUXX-ID assay is the only available kit for the simultaneous monitoring of all three major ABC reporter proteins with the ability to profile individual pump activity. Applications: Flow Cytometry, Fluorescence microscopy .