Quality assurance in RT-PCR-based BCR/ABL diagnostics - results of an interlaboratory test and a standardization approach

Here we describe the results of an interlaboratory test for RT-PCR-based BC R/ABL analysis. The test was organized in two parts. The number of particip ating laboratories in the first and second part was 27 and 20, respectively . In the first part samples containing various concentrations of plasmids w ith the ela2, b2a2 or b3a2 BCR/ABL transcripts were analyzed by PCR. In the second part of the test, cell samples containing various concentrations of BCR/ABL-positive cells were analyzed by RT-PCR. Overall PCR sensitivity wa s sufficient in approximately 90% of the tests, but a significant number of false positive results were obtained. There were significant differences i n sensitivity in the cell-based analysis between the various participants. The results are discussed, and proposals are made regarding the choice of p rimers, controls, conditions for RNA extraction and reverse transcription.