PCR ( models : ExtraGene 3200 and 9700 ) performance analysis

The polymerase chain reaction (PCR) is an easy, economic, convenient and biochemical technology in molecular biology for the amplification of thousands to millions of copies of a particular DNA sequence. The method consists of repetitive cycles of three steps: denaturation, hybridization, and polymerase extension, that raising temperature to break hydrogen bonds for formation of the single strand DNAs, then lowering temperature to allow the primers to anneal to the template DNAs, at last increasing temperature to the optimal condition for the Taq DNA polymerase to perform the polymerization. Because that the appropriate temperature and reaction time will be modulated based on the length and the specificity of the primers and the templates, the progresses of the PCR machine evolve the PCR reaction. Presently PCR technology is widely used in DNA cloning for sequencing, DNA-based phylogeny, functional analysis of genes, the diagnosis of hereditary diseases, the identification of genetic fingerprints, and the detection and diagnosis of infectious diseases. This report analyzes and compares two PCR machines: ExtraGene 3200 and 9700, with other brands of PCR machines on the performance of the PCR reaction, such as semiquantitative PCR with serial dilution of the templates or different number of cycles, the touchdown PCR, and the gradient PCR. The last two experiments only apply to the 9700 model. The results show that the 3200 model takes less time than other PCR machine in the completion time. The 9700 model performs as well as other PCR machines in touchdown PCR and gradient PCR, and since the model can set simultaneously in the temperature gradient of 12, to enhance its usefulness.