Patent ID: 8206924

Claim:
A method for amplifying a trace amount of mRNA, comprising: adding a dummy RNA to a solution containing the trace amount of mRNA, so as to prepare a mixed solution; synthesizing an anti-sense DNA by reverse transcription that uses the RNA in the mixed solution as a template; synthesizing a sense DNA which is complementary to the anti-sense DNA thus synthesized, so as to generate a double-strand DNA made of the sense DNA and the anti-sense DNA; ligating an RNA polymerase promoter sequence to the double-strand DNA thus generated, on a sense DNA 5′ end side of the double-strand DNA, so as to prepare a double-strand DNA for amplification, wherein ligating the RNA polymerase promoter sequence includes ligating the promoter sequence to both ends of the double-strand DNA thus generated, and cleaving the promoter sequence off from the double-strand DNA only on the sense DNA 3′ end side; and amplifying, by using RNA polymerase, an RNA from the double-strand DNA for amplification.