Patent ID: 8828662

Claim:
A method for detecting the possible presence of microsatellite instability in a biological sample comprising: (i) measuring, in the biological sample, the mRNA expression level of a first transcript of a human MLH1 gene containing the nucleotide sequence of SEQ ID NO: 1 at the 5′-terminus thereof and the mRNA expression level of a second transcript of a human MLH1 gene containing the nucleotide sequence of SEQ ID NO: 2 at the 5′-terminus thereof using a primer pair (a) and a primer pair (b), wherein the primer pair (a) is a combination of a primer comprising the nucleotide sequence as shown in SEQ ID NO: 6 with a primer comprising the nucleotide sequence of SEQ ID NO: 7, and wherein the primer pair (b) is a combination of a primer comprising the nucleotide sequence as shown in SEQ ID NO: 8 with a primer comprising the nucleotide sequence of SEQ ID NO: 7, and wherein the expression levels are measured using a real-time PCR method; and (ii) comparing the expression levels measured in (i), wherein a mRNA expression level of the second transcript that is higher than the mRNA expression level of the first transcript indicates the possible presence of microsatellite instability.