Double-palindromic hairpin probe, preparation method thereof and application of double-palindromic hairpin probe in microRNA detection

Abstract

The invention provides a double-palindromic hairpin probe, a preparation method of the double-palindromic hairpin probe, and application of the double-palindromic hairpin probe in microRNA (Ribonucleic Acid) detection. The double-palindromic hairpin probe DP-HP comprises a target recognition region, an endonuclease recognition site, an intramolecular complementary region, a double-palindromic sequence and a fluorescence resonance energy transfer group, and can trigger circulating strand displacement amplification in the presence of target miRNA-21 to generate a large number of polymerization and cleavage products so as to realize cascade amplification of fluorescence signals. A chain structure is formed through self-assembly based on a cascade signal amplification technology of a double-palindromic hairpin probe, specific detection of a trace amount of miRNA-21 is realized through a one-step method under the synergistic effect of polymerase and endonuclease, the method does not need an exogenous primer, is simple and convenient to operate, has the detection limit as low as 1.06 aM, can distinguish single-base mismatched sequences, and has a good application prospect. The kit is successfully applied to detection and analysis of clinical samples, and a high-sensitivity and high-specificity detection tool is provided for early diagnosis of cancers.

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