小中大
估计您是刚开始设计定量，所以困惑可以从下面这篇文章得到：
Analysis of Relative Gene Expression Data Using Real-Time Quantitative PCR and the 2−ΔΔCT Method
Kenneth J. Livaka and Thomas D. Schmittgenb, 1
a Applied Biosystems, Foster City, California, 94404 b Department of Pharmaceutical Sciences, College of Pharmacy, Washington State University, Pullman, Washington, 99164-6534
Abstract
The two most commonly used methods to analyze data from real-time, quantitative PCR experiments are absolute quantification and relative quantification. Absolute quantification determines the input copy number, usually by relating the PCR signal to a standard curve. Relative quantification relates the PCR signal of the target transcript in a treatment group to that of another sample such as an untreated control. The 2−ΔΔCT method is a convenient way to analyze the relative changes in gene expression from real-time quantitative PCR experiments. The purpose of this report is to present the derivation, assumptions, and applications of the 2−ΔΔCT method. In addition, we present the derivation and applications of two variations of the 2−ΔΔCT method that may be useful in the analysis of real-time, quantitative PCR data.
Methods
Volume 25, Issue 4, December 2001, Pages 402-408
