AN HOMOGENEOUS ASSAY FOR MEASURING THE UPTAKE AND EFFLUX OF RADIOLABELED DRUGS IN ADHERENT CELLS

We have developed an homogeneous assay to measure the uptake and efflu x of [C-14]adriamycin (doxorubicin hydrochloride) in human squamous lu ng carcinoma cells (SKMES-1), using 96 well scintillating microplates. The assay was also used to examine the effect of inhibitors of multid rug resistance in adriamycin resistant cells (SKMES-1/ADR). The effect of adriamycin on cell growth and viability was examined by continuous monitoring of the uptake of [C-14]thymidine. The non-invasive nature of these assays, and the ease of use of the microplates, suggests a ro le in screens for, and characterisation of, novel chemotherapeutic or chemosensitizing agents. (C) 1997 Elsevier Science B.V.