The invention discloses a method for generating a hairpin ring for enriching
mutation or
allele information. According to the invention, a
primer extension binding region containing more than 8 basic groups is arranged on a selector; when the selector extends by taking the target
DNA as a template and is denatured and renatured, a 3 '-terminal suspended hairpin structure is formed by itself, a 3'-terminal suspended sequence is digested under the action of T4
DNA polymerase, a sequence at a gap is supplemented, a hairpin structure
intermediate product is formed, and the hairpin structure is used for synthesizing
a DNA sequence by taking a
genome as a template. And carrying out targeted enrichment on polymorphic site information (
wild type and
mutant type), and then carrying out information decoding through next-generation sequencing. The method is used for enriching information of rare
mutation sites, only common dNTP is needed for single primer amplification, then T4
DNA polymerase is added for digesting mismatched sequences in a stem region, completely paired sequences are reserved, and the purpose of enriching the rare
mutation sites is achieved. And more than 1000 probes can be subjected to multiple analysis in one PCR tube by using standard laboratory equipment.