Screening library of nucleic acid aptamers

Abstract

The invention discloses a screening library of nucleic acid aptamers, belonging to the technical field of bioanalysis and bioengineering. The screening library comprises the following specific nucleotide sequences: 5'-ACCGACCGTGCTGGACTCT(N40)ACTATGAGCGAGCCTGGCG-3' as the library, 5'-ACCGACCGTGCTGGACTCT-3' as the forward primer, and 5'-CGCCAGGCTCGCTCATAGT-3' as the reverse primer. According to the invention, the library has short fixed sequences with the length being close to the minimum length and long random sequences, and the diversity of single-chain oligonucleotides in the library is fully guaranteed; the unique design of the fixed sequences (primer sequences) in the library can conduct PCR amplification at high annealing temperature, can effectively inhibit non-specific products and does not influence the amplification of target products, which is proved in symmetric PCR amplification, asymmetric PCR amplification and real-time fluorescent quantitative PCR amplification. The random single chain oligonucleotide library provided by the invention has excellent performance and provides guarantee for successfully screening nucleic acid aptamers of bio-target.

Description

technical field [0001] The invention belongs to the technical field of biological analysis and engineering, and specifically relates to a self-designed random single-stranded oligonucleotide library for nucleic acid aptamer screening and matching primers. Background technique [0002] Nucleic acid aptamer (aptamer) is an artificial single-stranded nucleic acid ligand of a biomolecule, which is screened from a random single-stranded oligonucleotide library by SELEX (Systematic Evolution of Ligands by Exponential Enrichment) technology. Nucleic acid aptamers have similar functions to antibodies and can be used to recognize target molecules, and their sensitivity and specificity can be superior to antibodies. In the preparation process of both, nucleic acid aptamers have obvious advantages in terms of targets. The targets for screening aptamers can be as small as inorganic molecules, as large as complete living cells, or even tissues, while the targets for preparing antibodies...

AI Technical Summary

Problems solved by technology

Generally speaking, there is a very unique phenomenon in the PCR amplification of random single-stranded oligonucleotide libraries, that is, with the increase of the number of cycles, non-specific products of various sizes increase rapidly, and the target bands continue to increase. Reduced, which seriously interferes with the preparation of sub-libraries, and even leads to screening failure

The reason for this special phenomenon is mainly the existence of random sequences in the library, because the sequence diversity of the library reaches 10 14-15 , partial base local pairing between single-stranded oligonucleotides is difficult to avoid, and mismatches between primers and certain oligonucleotides are also difficult to eliminate

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