Competitive PCR quantitation utilizing a microtiter plate based format for the detection of PCR products

In microbiology, the polymerase chain reaction (PCR) has become an important tool for the analysis of clinical samples. For example, it led to the detection of Hepatitis-B Virus DNA (HBV-DNA) in patients with serological patterns not previously associated with active infection (1). PCR-based assays are also more sensitive than conventional tests for the detection of many other infective agents, like Hepatitis-C Virus (HCV), herpes viruses, or Legionella pneumophila (2). In some cases, however, the detection of the nucleic-acid sequences of a certain infectious agent is not very informative. Here is a quantitative information of the amount of nucleic acid needed. DNA quantitation is useful for monitoring the viral load during antiviral therapy (3), in estimating the degree of infectiousity of individuals (4,5), and (e.g., for herpes viruses) to differentiate between latent and active infection. Owing to its sensitivity, quantitative PCR is the most sensitive technique for the quantitation of nucleic acids and therefore has been investigated in detail.