Objective: To detect the bcr/abl fusion gene in chronic myeloid leukemia (CML) for assisting in clinical diagnosis.

Methods: Fluorescence in situ hybridization (FISH) and nested reverse transcription polymerase chain reaction (RT-PCR) were used.

Results: Out of 16 CML patients, the results of FISH was not consistent with that of nested RT-PCR in 3 cases. When compared with the results of Northern blot, it was found that nested RT-PCR was more sensitive than FISH, but might give false positive results. Moreover, FISH was the easier method for detecting rarer types of bcr/abl transcripts. For detecting the latter occasions nested RT-PCR have to design several specific primers.

Conclusions: It could take their advantages of applying FISH and nested RT-PCR at the same time to make the results more accurate and reliable for the diagnosis, prognosis and monitor of minimal residual disease.