MICROBIAL MONITORING DURING BIOAUGMENTATION WITH DEHALOCOCCOIDES - Bioaugmentation for Groundwater Remediation - page 177

6.5 QUANTITATIVE-PCR
qPCR is a powerful molecular tool used to determine the concentration of specific genes
of interest in environmental samples. Both qPCR and its predecessor, PCR, are now routinely
used in laboratory analyses of DNA extracted from a wide variety of live or dead organisms.
Fields as diverse as environmental remediation, forensics, medicine, paleontology and archae-
ology now use data acquired through PCR on a regular basis. These techniques also are
commonly referenced in film, television programming, litigation trials and print media.
While the origins of the PCR process extend back into the early 1970s, with qPCR developed
in the 1990s, both still are undergoing rapid advancement.
Before any analysis and interpretation of qPCR data can be performed, an understanding
of the basic principles and limitations of PCR is required. The following section introduces
common terminology, provides a summary of the underlying science and a general example of
qPCR use in environmental remediation. This section focuses solely on the use of qPCR for
microbial DNA analysis, although the science and techniques are generally the same irrespec-
tive of the source of DNA.
6.5.1 Description and General Methodology
PCR techniques use one of several purified microbial enzymes to produce large numbers of
nearly identical copies of specific pieces of DNA (Figure 6.5 ). These enzymes are known
Figure 6.5. Schematic diagram of qPCR.