Patent ID: 7402386

Claim:
A method for amplification of a template DNA, comprising: (a) incubating a reaction mixture, said reaction mixture comprising: (i) a template DNA: (ii) a first primer, wherein the first primer is hybridizable to a multiplicity of template sites, wherein the first primer is a population of different composite primers each comprising an RNA portion and a 3′ DNA portion, wherein each composite primer comprises a 3′ random sequence, and wherein each composite primer is a tailed primer that comprises a 5′ portion that is not hybridizable to the template DNA tinder conditions in which the first primer hybridizes to the template DNA; (iii) a DNA-dependent DNA polymerase; and (iv) an RNA-dependent DNA polymerase; wherein the incubation is under conditions that permit generation of a complex comprising an RNA/DNA heteroduplex, wherein said complex comprising an RNA/DNA heteroduplex is produced by hybridization of the first primer to the template DNA, primer extension to generate a first primer extension product, hybridization of a second primer to the first primer extension product, and extension of the second primer to generate a second primer extension product; and (b) incubating a reaction mixture, said reaction mixture comprising (i) at least a portion of the reaction products generated according to step (a); (ii) an amplification primer, wherein said amplification primer is a composite primer comprising an RNA portion and a 3′ DNA portion, wherein the amplification primer comprises some of the sequence of the first primer, and wherein the first primer and the amplification primer are different primers; (iii) a DNA-dependent DNA polymerase; and (iv) an agent that cleaves RNA from an RNA/DNA heteroduplex; wherein the incubation is under conditions that permit RNA cleavage, primer hybridization, primer extension, and displacement of the first primer extension product when its RNA is cleaved and another amplification primer binds to the second primer extension product and is extended, such that primer extension and strand displacement are repeated, whereby multiple copies of a an amplification product are generated.