Multicentric evaluation of the MDR phenotype in leukemia : Phenotypic and genotypic analyses of multidrug resistance (MDR) in clinical hospital practice

The wide discrepancies in the frequency of 'positive' samples for multidrug resistance (MDR) phenotype within the same type of tumor observed in the literature justified the need for the definition of consensus recommendations. To define standard techniques of MDR phenotype measurement, we ran a large multicentric evaluation of the different methods available. Thirty-six French centers participated in the study, and 742 samples of 2-10 x 10 6 viable cells were sent by overnight express mail between December 1993 and February 1996 (...)