Patent ID: 7176002

Claim:
A method for amplifying target DNA by polymerase chain reaction (PCR) comprising: providing a length of a PCR amplified product that is primed at a single specified site on a target DNA; preparing a mixture, of (1) said target DNA, comprising multiple DNA sequences, (2) a set of oligonucleotide primers, each primer comprising (i) a 3′ specific region, wherein a sequence of said 3′ specific region is selected to hybridize to the specified site on the target DNA, and wherein said specified site on the target DNA is chosen according to the length of the PCR amplified product that is primed at the specified site on the target DNA, (ii) a random region, and (iii) a 5′ universal region, wherein said universal region is selected to meet a requirement of a PCR primer and serves as a first universal priming site (U1) for further PCR amplification with a complementary primer, wherein the 5′ universal region, serves as an entire first universal priming site independently of the random region and the 3′ specific region, (3) a DNA polymerase, and (4) multiple deoxynucleoside triphosphates (dNTPs) under conditions such that said PCR primers anneal to target DNA; and performing a polymerase chain reaction (PCR) to amplify the target DNA sequences in said target DNA, whereby a PCR amplified product is formed incorporating said first universal priming site (U1).