Kyoto, Japan, November 5, 2001--- The Biomedical Group of Takara Shuzo Co., Ltd. announced today that the scientists had originally developed a novel method to detect SNP (single nucleotide polymorphysm) and mutation. The method is called UCAN. The UCAN method can allow completion of SNP typing in about one hour without a special equipment such as a thermalcycler which is required for polymerase chain reaction (PCR).

UCAN method employs an oligodeoxyribonucleiotide interrupted by oligoribonucleotide (DNA-RNA-DNA; DRD primer) as a primer for DNA polymerase reaction. In addition, 3' terminal of the primer is chemically blocked to prevent elongation reaction by the polymerase. When there is a mismatch between a template and a RNA portion of the DRD primer sequence, RNase H can not cut the RNA portion. Under this situation, DNA polymerization never occurs, because the 3' terminal of DRD primer remains blocked. When there is the mismatch between the sequences, RNase H digests the RNA portion of the DRD primer. This results in removal of the blocked terminal from the primer, so that the polymerization can occur. Thus, SNP can be clearly detected by UCAN method upon the presence or absence of the elongation reaction.

To show the usefulness of UCAN method, researchers of the Group identified a target SNP in c-Ki-ras (one of human cancer genes) and CYP2C19 (a member of drug-metabolizing cytochrome P450 family). The detection of the SNP from 10 ng of human genomic DNA could be completed in one hour. Thus, UCAN method can be used for efficient and economical identification of SNP and mutation. The Biomedical Group believes that the method will serve for advances in pharmacogenomics.

This article is translated from press release in Japanese for your convenience.