Author(s): Sonia Tomar*
Polymerase chain reaction is a popular method in molecular diagnostic in which small amount of DNA undergo five steps of denaturation, primer attachment, again repeating to form number of copies, in analogous way continued round of amplification many identical copies can be produced. There are numerous factors which play significant role in this technique like denaturation temperature (94°C), Annealing temperature (40 to 60°C), Extension temperature (72°C) also with type of DNA polymerase enzyme use like natural (Taq) or recombinant (Amplitaq). All polymerase varies in term of their properties (Their thermostability, exonuclease activity, extension rate, reverse transcriptase activity, molecular weight, resulting DNA end and so on). Its applicability is very wide ranging from genetic fingerprinting, forensic investigation, cloning, mutation detection, microarray. It is still in its development phase new advances are made every day, still need to overcome some of its drawback like variation in parameters, starting material quantification.