ctDNA database-building kit and database-building method

Abstract

The invention belongs to the field of molecular genetics and specifically relates to a ctDNA database-building kit and a database-building method. The ctDNA database-building kit comprises a hairpin joint A, a double-link joint B and a primer set; the hairpin joint A comprises a joint A1 and a joint A2; sequences of the joint A1 and the joint A2 are respectively SEQ ID NO.1 and SEQ ID NO.2; 3' endof the joint A2 is modified with biotin; the double-link joint B comprises a joint B1 and a joint B2; sequences of the joint B1 and the joint B2 are respectively SEQ ID NO.3 and SEQ ID NO.4; the primer set comprises an amplification primer and a joint primer; the sequence of the amplification primer is SEQ ID NO.5; the sequence of the joint primer is SEQ ID NO.6-7. The kit provided by the invention is high in sensitivity and is capable of improving ctDNA sequencing flux and sequencing accuracy.

Description

technical field [0001] The invention belongs to the field of molecular genetics, and in particular relates to a ctDNA library building kit and a library building method. Background technique [0002] ctDNA, or circulating tumor DNA, is the residue left in plasma by circulating tumor cells and tumor tissues in the body during cellular metabolism. Scientific research has found that high-throughput analysis of ctDNA using sequencing technology can guide the selection of anti-tumor drugs, efficacy evaluation, prognosis judgment, and even early detection and early diagnosis based on gene mutation information. However, the concentration of ctDNA in plasma is extremely low, and most of them are small fragment molecules, which are difficult to extract, have a large amount of loss, and have low detection sensitivity, which brings challenges to the preparation of sequencing libraries. The current method of ctDNA library construction on the market is to fill in the ends of double-stra...

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Problems solved by technology

However, due to the highly fragmented characteristics of ctDNA, some ctDNA cannot be filled with adapters, resulting in the loss of ctDNA, making some gene mutation sites undetectable, which limits the detection sensitivity

[0003] The patent application with the application number CN201710116455.3 attempts to solve the above problems by using single-stranded ligase to decompose the ligation linker. Although the detection sensitivity is improved to a certain extent, the single-stranded ligase has a strong circularization effect on single-stranded DNA molecules, and When single-strand ligase ligates, there is a base preference for DNA single-strand ends in the order of T>A>G>C from strong to weak, which affects the detection sensitivity. Therefore, more effective solutions are still needed to make up for existing technologies. lack of

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