FLOW CYTOMETRIC ANALYSIS OF THE MULTIPLE-DRUG RESISTANCE PHENOTYPE

Laser flow cytometry is increasingly used for quantitation of cellular fluorescent drug retention, effect of efflux blockers and for express ion of drug resistance related cellular surface markers. Several intri nsic and extrinsic factors can affect the results obtained from drug r etention functional assays and lead to artifacts. In the present study , we have used a panel of well-characterized parental and drug resista nt cell lines, fluorochromes and efflux blockers to identify the possi ble sources of artefacts in flow cytometric analysis of the multiple d rug resistance phenotype.