Analysis of Relative Gene Expression Data Using Real- Time Quantitative PCR and the

group The two most commonly used methods to analyze data from such as an untreated control or a sample at time zero real-time, quantitative PCR experiments are absolute quantifica- in a time-course study. tion and relative quantification. Absolute quantification deter- Absolute quantification should be performed in situ- mines the input copy number, usually by relating the PCR signal to a standard curve. Relative quantification relates the PCR signal ations where it is necessary to determine the absolute of the target transcript in a treatment group to that of another transcript copy number. Absolute quantification has sample such as an untreated control. The 2 2DDCT method is a been combined with real-time PCR and numerous re- convenient way to analyze the relative changes in gene expression ports have appeared in the literature of