Method for low-frequency mutant-enriched sequencing of DNA of exfoliative cells

The invention provides a method for low-frequency mutant-enriched sequencing of DNA of exfoliative cells. The method includes the steps of extraction of the DNA of the exfoliative cells, break of the DNA, sample DNA library construction, universal library TT-COLD PCR amplification enrichment, probe enrichment capture, captured product PCR and computer sequencing and positive-negative double-strand error-correction low-frequency information analysis, to be more specific, performing universal adapter primer based TT COLD PCR on all types of mutant to realize first-stage mutant-enriched amplification; designing an enrichment probe chip to replace a probe designed for a human genome reference sequence hg19 with a probe designed based on mutation bases for hot point mutants, keeping probes at other sites unchanged, and performing second-stage enriched capture. 12bp own sequences inserted into two ends of the DNA in library construction are taken as labels for positive and negative double-strand error correction comparison, data utilization rate is increased, low-frequency accurate detection is realized, and high-specificity detection for 0.01% low-frequency mutations can be achieved.