ASSAY AND REAGENT KIT FOR THE QUANTITATIVE IN VITRO DETERMINATION IN BIOLOGICAL SPECIMENS OF THE ACTIVITY OF PROTEINS CAUSING MULTI-DRUG RESISTANCE IN TUMORS

摘要

Disclosed herein are a diagnostic assay method and reagent kits for the quantitative in vitro determination of the activity in biological specimens of MDR proteins causing multi-drug resistance in tumors. The method of the invention is based on the measurement of the accumulation rate of a compound within the cells of the specimen (advantageously by fluorescence measurement) which compound is not a good substrate of the MDR protein present in the sample, not cell permeable and is being formed within the cells, by enzymes generally present in the cells, from a compound which is a good substrate of said MDR protein, cell permeable and is added to the specimen in vitro. Based on the method of the invention, it is possible to calculate an MDR activity factor (MAF) value that is, within the diagnostically relevant range, characteristic of the MDR activity, i.e. to the multi-drug resistance level of the specimen.