Digestion probe in PCR detection and kit thereof

Abstract

The invention relates to a digestion probe in PCR (Polymerase Chain Reaction) detection and a kit thereof. The digestion probe, has a structure of digestion probe 5' end-probe middle part-probe 3' end. By adjusting the digestion probe structure and introducing basic group modification, so that the binding capacity of the 5' end of the digestion probe is relatively weak, and the binding capacity of the 3' end of the digestion probe is relatively strong, therefore, on the premise of ensuring the digestion efficiency of a digestion target fragment, the digestion specificity is enhanced, detection signals corresponding to the target fragment are enriched more effectively, finally, the detection sensitivity is greatly improved, and liquid biopsy can be achieved.

Description

technical field [0001] The invention belongs to the detection technology of clinical molecular diagnosis in the field of biomedicine. The invention relates to a digestion probe and a kit in PCR detection, in particular to a wild-type target fragment digestion probe and its application in the detection of microsatellite instability, which can improve the detection sensitivity of microsatellite instability (MSI), especially can be applied MSI detection method for liquid biopsy. Background technique [0002] Microsatellite sequence refers to a short tandem repeat structure with a core sequence of 1 to 6 bases, and these repeat sequences are distributed throughout the human genome. The phenomenon of microsatellite sequence length change caused by insertion or deletion mutations during DNA replication is called microsatellite instability (Microsatellite Instability, MSI). [0003] Microsatellite instability (MSI) phenomenon exists in many solid tumors. The tumor types with the...

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Problems solved by technology

Although the former is relatively simple to operate, it requires higher reaction conditions and it is difficult to detect multiple microsatellite sites at the same time.

The reaction conditions of the latter are relatively stable, and multiple sites can be detected at the same time, but because the digestion efficiency is not high enough, there are still a very large number of wild-type signals in the final detection results, which affects the detection sensitivity, especially in multiplex amplification. This detrimental effect is particularly pronounced in increasing

[0013] This phenomenon exists not only in microsatellite instability (MSI), but also in conventional PCR amplification, because in conventional detection, the base difference between the target fragment and other fragments is relatively large, and its impact on sensitivity is limited. However, if the fragments with other target fragments can be digested before amplification, the sensitivity will be greatly increased in the PCR amplification of target fragments

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