PCR products are used to amplify a section of DNA so that a
particular strand can be identified, extracted and either cloned or manipulated
for further scientific research. The usual PCR products
that are used for this procedure include primers, Mg ion and dNTPs among
others. PCR purification is basically the cleanup and removal of these products
from the DNA sample which, although were vital for the PCR reaction, have now
become contaminants to the sample.
PCR purification is not always necessary especially if the
PCR product comprises less than a 20% volume the assembly reaction. However if
the PCR product is in excess or there have been other impurities introduced
into the sample, then purification will be necessary to avoid the primers and
impurities from interfering with the sequencing or cloning of the DNA strand. Sometimes PCR purification may also be necessary if there is a substantial amount of unused primer and other miscellaneous amplification products. Also, if your intension is simply to pass the DNA sample through an agarose gel for visual diagnostics only, then there may be not need to perform PCR purification on it, since the excess or unused primer will not adversely affect the procedure.
The gist of PCR purification is to separate the molecules
courtesy of their varying densities and with the help of a strong centrifugal
force. So why is PCR purification so significant? The purity of DNA is vital
for the success of most methods used in micro biology, bio chemistry, genomics
and clinical research. The success or failure of downstream experiments depends
greatly on the adequacy of the sample that is being tested.
Working with uncorrupted and uncontaminated DNA samples
ensures that the researcher is able to extract a sufficient amount of genomic
or plasmid DNA strand sample from that limited source, so that it is enough to
satisfy your research requirements. Also the PCR purification process reduces
the number of contaminants in the DNA sample that may compromise scientific
experiments or significantly shorten the life span of the samples so that they
do not last till the completion of the experiment. The significance of the PCR
purification is that starting out with a contaminated sample creates a high
probability that you will get the wrong data or results. Although other factors
may contribute to the failure of the experiment, starting off with a clean
sample greatly increases the probability of success. PCR purification also
helps the researcher preserve the purity and integrity of the nuclear acids
which are the main components of cells and DNA strands that facilitate the
progress of most experiments.
As science and technology advances, and more technical DNA
and genetic research is required, it will be more vital to have the purest
forms of DNA. More advanced and delicate DNA based experiments in search of
vaccines, cures for neuro-genetic diseases and disorders among others will
require the purest samples for the most accurate results.
There are numerous commercial PCR purification kits on the
market that provide this service in a quick and effective manner. These kits
are fast, convenient, effective and quite simple to use. With all these
shimmering attributes, the kits are a bit costly with the best quality kits
ranging from USD$ 200 to USD$ 800.
If you are tight for money or simply believe in stretching a
dollar, you can purchase filter plates that are not only cheaper than
purchasing the entire kit, but are equally easy to use.
It is vital to remember that, even though you are trying to
save a few bucks on this PCR purification process, you should only reuse these
filter plates once for efficiency sake.