Polymerase Chain Reaction* (PCR) is a process where millions of
copies of DNA are amplified from a single copy, or low copy number
template. This reaction is fundamental to almost all applications
requiring a high copy number of starting material and is used in all
laboratories working with DNA and RNA.
Because of the high copy number generated during PCR, it is essential
to prevent possible contamination of the PCR reaction. Precautions must
be taken during the sample and reagent preparation steps to minimize
this risk. In addition to good laboratory practice, the ideal PCR
laboratory should consist of three areas, each isolated from the other.
Reagents should be prepared in the reagent preparation area and
transferred to the sample preparation area, through a pass box, or
inside closed containers. After preparation of the final reaction mix,
the tubes should be transferred to the amplification area, again through
a pass box or in a closed container. The PCR amplification and results
analysis takes place in this area.
To guarantee contaminant-free samples, it is essential to work in an
environment where the air quality is controlled. This should form part
of the equipment in the sample preparation area.