ABSTRACT
Objective To study the screening of trace amount mutation of BRAF V 600E gene for avoiding the appearance of ineffective treatment in cancer patients .Methods The internal competitive amplification fragments were used to improve the inhibition of wild-type blocking (WTB) probe on wile-type BRAF V600E gene to increase the detection efficiency of BRAF V600E genotype of trace amount mutation occurrence .Re-sults When the template DNA concentration was 50 -200 ng/μL ,the constructed trace amount gene muta-tion real time fluorescence quantitative detection method could completely block the amplification of the wild-type BRAF V600E gene .The sensitivity of this assay reached as high as 0 .1％ ,which was in line with the sen-sitivity requirement for the gene trace amount mutation detection technique .In the colorectal biopsy tissues from 50 cases of suspected colorectal cancer ,8 cases (16 .0％ ) of BRAF V600E gene trace amount mutation were detected by using this constructed method ,which had higher detection rate .Conclusion The constructed gene trace amount mutation detection method can make the rapid ,simple and low cost quantitative analysis for BRAF V600E gene trace amount mutation in clinical samples .