Detection of KRAS mutations in tumor cells using biochips

Molecular Biology (Impact Factor: 0.72). 10/2011; 45(5):797-803. DOI: 10.1134/S0026893311040042

ABSTRACT Somatic mutations in the KRAS gene are important markers of some types of tumors, for example, pancreatic cancer, and may be useful in early diagnostics.
A biochip has been developed which allows deter-mining most frequent mutations in 12, 13, and 61 codons of the KRAS gene. To increase the sensitivity of the method and to enable the analysis of minor fractions of tumor cells in clinical
samples, the method of blocking wild type sequence PCR amplification by LNA-oligonucleotides has been used. The product of
LNA-clamp PCR was further hybridized with oligonucleotide probes, immobilized on the biochip. The biochip was tested with
42 clinical DNA samples from patients with pancreatic cancer, mostly duct adenocarcinomas. As reference methods, RFLP analysis
and sequencing were used. The developed approach allows detecting somatic mutations in the KRAS gene if the portion of tumor cells with mutation is at least 1% of the whole cell population.

Keywordssomatic mutations–tumor–
KRAS gene–biochips

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