Quantitative RT- PCR is modern method for analysis of expression of genes. In this method, purified RNA is separated by cell samples. It provides qualitative or semi quantitative information at mRNA levels. Variations within the quantification method can arise because of the DNA integrity, enzyme proficiency and other chemical factors. This quantification process is easily understood by standardization systems (normalization method). It’s an advance and upgraded version of normal PCR machine that facilitates quantitative analyses of organic phenomenon of basic biology (RNA and DNA), medicine, RNAi validation, pathogen detection, genetic testing, and disease diagnostics. It allows the continuous monitoring of the amplification process as it happens and uses fluorescent reporter dyes to combine the amplification and detection steps. It is totally based on measuring the proliferation of fluorescent signal, which relates to the amount of DNA produced during each PCR cycles. The range of the qRT-PCR technique makes it applicable across an intensive range of experimental environments and allows experimental evaluation between normal and abnormal conditions of samples.