Application of peptide nucleic acid to the direct detection of deoxyribonucleic acid amplified by polymerase chain reaction

Double-stranded DNA amplified by polymerase chain reaction (PCR) was detect ed by peptide nucleic acid (PNA) using a BIAcore(TM) 2000 biosensor based o n surface plasmon resonance (SPR). PNA is an artificial oligo amide that is capable of forming highly stable complexes with complementary oligonucleot ides. We succeeded in the direct detection of double-stranded DNA, amplifie d by PCR with high-sequence specificity. It was shown that the target DNA w as available for detection over the range of 40-160 nM. Therefore, the dete ction limit was 7.5 pmol of the target DNA (143 bases, applied volume 30 mu l) Our DNA detection system, the combination of BIAcore(TM) and the probe PNA, could detect the target DNA with good reproducibility. In this report, we show that our system is a powerful tool for the diagnosis of pathologic ally significant DNA. (C) 1999 Elsevier Science S.A. All rights reserved.