Rapid diagnosis of acute promyelocytic leukemia with the PML-RARA fusion gene using a combination of droplet-reverse transcription-polymerase chain reaction and instant-quality fluorescence in situ hybridization

•The droplet-RT-PCR can detect the PML-RARA gene within 26min.•The IQ-FISH yielded clear signals after 60min of hybridization.•The IQ-FISH showed same positive signal ratios as conventional FISH.•We developed a rapid assay system for the PML-RARA fusion gene within 4h.