Method for detecting human microsatellite instability site, and use thereof

A reagent for the detection of human Microsatellite Instability (MSI) sites, wherein the sites is selected from sites 1-10 in chromosome hg38 (SEQ ID NO.:

• 1-10);
• wherein the reagent is selected from the following group:
• (a) The first primer pair for detecting MSI at chr3 site 1 (SEQ ID NO.:1), where the first primer pair comprises primers shown in SEQ ID NO.:11 and 12;
• (b) The second primer pair for detecting MSI at chr11 site 2 (SEQ ID NO.:2), in which the second primer pair comprises primers shown in SEQ ID NO.:19 and 20;
• (c) The third primer pair for detecting MSI at chr16 site 3 (SEQ ID NO.:3), in which the third primer pair comprises primers shown in SEQ ID NO.:23 and 24;
• (d) The fourth primer pair for detecting MSI at chr17 site 4 (SEQ ID NO.:4), where the fourth primer pair comprises the primers shown in SEQ ID NO.:25 and 26;
• (e) The fifth primer pair for detecting MSI at chr20 site 5 (SEQ ID NO.:5), where the fifth primer pair comprises primers shown in SEQ ID NO.:29 and 30;
• (f) The sixth primer pair for detecting MSI at chr2 site 6 (SEQ ID NO.:6), where the sixth primer pair comprises primers shown in SEQ ID NO.:13 and 14;
• (g) The seventh primer pair for detecting MSI at chr2 site 7 (SEQ ID NO.:7), where the seventh primer pair comprises primers shown in SEQ ID NO.:15 and 16;
• (h) The eighth primer pair for detecting MSI at chr6 site 8 (SEQ ID NO.:8), where the eighth primer pair comprises the primers shown in SEQ ID NO.:17 and 18;
• (i) The ninth primer pair for detecting MSI at chr14 site 9 (SEQ ID NO.:9), where the fourth primer pair comprises the primers shown in SEQ ID NO.:21 and 22;
• (j) The tenth primer pair for detecting MSI at chr20 site 10 (SEQ ID NO.:10), where the tenth primer pair comprises primers shown in SEQ ID NO.:27 and 28;
• any combinations of (a) to (j) above.

A method for detecting MSI in the sample to be tested, comprising steps:

• (S1) A PCR reaction system is provided, the PCR reaction system comprises samples to be tested as templates and primer pairs for amplification;
• and the primer pairs are selected from the following group:
• (a) The first primer pair for detecting MSI at chr3 site 1 (SEQ ID NO.:1), where the first primer pair comprises primers shown in SEQ ID NO.:11 and 12;
• (b) The second primer pair for detecting MSI at chr11 site 2 (SEQ ID NO.:2), in which the second primer pair comprises primers shown in SEQ ID NO.:19 and 20;
• (c) The third primer pair for detecting MSI at chr16 site 3 (SEQ ID NO.:3), in which the third primer pair comprises primers shown in SEQ ID NO.:23 and 24;
• (d) The fourth primer pair for detecting MSI at chr17 site 4 (SEQ ID NO.:4), where the fourth primer pair comprises the primers shown in SEQ ID NO.:25 and 26;
• (e) The fifth primer pair for detecting MSI at chr20 site 5 (SEQ ID NO.:5), where the fifth primer pair comprises primers shown in SEQ ID NO.:29 and 30;
• (f) The sixth primer pair for detecting MSI at chr2 site 6 (SEQ ID NO.:6), where the sixth primer pair comprises primers shown in SEQ ID NO.:13 and 14;
• (g) The seventh primer pair for detecting MSI at chr2 site 7 (SEQ ID NO.:7), where the seventh primer pair comprises primers shown in SEQ ID NO.:15 and 16;
• (h) The eighth primer pair for detecting MSI at chr6 site 8 (SEQ ID NO.:8), where the eighth primer pair comprises the primers shown in SEQ ID NO.:17 and 18;
• (i) The ninth primer pair for detecting MSI at chr14 site 9 (SEQ ID NO.:9), where the fourth primer pair comprises the primers shown in SEQ ID NO.:21 and 22;
• (j) The tenth primer pair for detecting MSI at chr20 site 10 (SEQ ID NO.:10), where the tenth primer pair comprises primers shown in SEQ ID NO.:27 and 28;
• any combinations of (a) to (j) above;
• (S2) the PCR reaction system of step (51) is subjected to PCR reaction to obtain an amplification product;
• (S3) The amplification product generated in step (S2) is analyzed to obtain the MSI of the sample to be tested;
• wherein taking the total number of detected sites P=5 as an example, If the number of MSI sites in the sample PMSI≥2, it is judged to be highly unstable (MSI-H);
• If the number of MSI sites in the sample PMSI=1, it is judged to be lowly unstable (MSI-L);
• If the number of MSI sites in the sample PMSI=0, it is judged to be stable (MSS).