The Protein Man's Blog | A Discussion of Protein Research

The polymerase chain reaction is a widely used technique for amplification of DNA products for genetic studies, DNA fingerprinting, clinical diagnostics, forensics and many more. Non-specific amplification of PCR products and the formation of primer dimers are the major problems during a PCR reaction. The main reason is due to the mild activity of polymerases at low temperatures and the binding of primers at nonspecific sites. As a result, even before the start of PCR amplification non-specific gene products and primer dimers are formed. The yield of target DNA is reduced as the polymerase, nucleotides, and primers are consumed. Hot start PCR methods are used to avoid this problem. 

Genomic DNA extraction is an important part of the process when it comes to studying DNA. Pure DNA, separated from the proteins and fluid of cells, is needed on its own in order to be used for various molecular applications. These analyses can include cloning, sequencing, electrophoresis, and fingerprinting.

Multiplex PCR is a technique used to amplify multiple target sequences in a single PCR reaction using multiple primer sets. Multiplex PCR was first reported by Chamberlain et al. in 1988. This method is used to detect deletions, polymorphisms, mutations, etc., This method is also used to detect different viral, bacterial and other pathogens in a single tube. This method consumes less time and effort in obtaining the results, but problems posed during multiplex PCR include poor sensitivity, specificity, and problems in amplification of some specific targets.

While phenol extraction is one of the commonly used methods in purifying DNA samples (i.e., removing proteins from cell lysates during DNA preparation), some people do not fully understand how and why it works. Read on to learn and appreciate how phenol extraction works.