Patent ID: 8053215

Claim:
A nucleic acid sequence amplification method using polymerase chain reaction (PCR), which method comprises: a step of injecting into a reaction vessel a sample comprising a template DNA having target nucleic acid sequences to be amplified and DNA polymerase, and at least two oligonucleotide primers complementary to the 3′ terminus of each of the target nucleic acid sequences; and a step of maintaining a spatial temperature distribution in the sample by contacting thermally with the sample a plurality of heat sources which supply heat to, or remove heat from regions of the sample such that a relatively high temperature region is located lower in height than a relatively low temperature region, wherein the spatial temperature distribution comprises spatial regions fulfilling temperature conditions suitable for (i) a denaturation step in which double stranded DNAs become separated to single stranded DNAs, (ii) an annealing step in which the single stranded DNAs formed in the denaturation step hybridize to the primers to form DNA-primer complexes, or (iii) a polymerization step in which the primers in the DNA-primer complexes are extended by the polymerization reaction, and wherein the spatial temperature distribution is a temperature distribution that induces circulation of the sample by thermal convection so that the denaturation, annealing, and polymerization steps occur sequentially and repeatedly inside the sample.