This is a program for the normalization of real-time quantitative PCR data based on the delta(delta(Ct)) method. It calculates the mean/median and confident interval for the normalized copy number, which follows a log-normal distribution. Two methods are supported, one relying on resampling approach to determine the empirical distribution of the normalized copy number, and the other doing calculation with an approximate form of analytical formula. A prerequisite for the delta(delta(Ct)) method is that a reference sample and a reference marker are both required in the experiment. To use this program, just edit the raw Ct value with a spreadsheet program, such as MS Excel, in a format like this, then copy/paste to the following window. Please add the word "control" to the name of reference sample and marker (see example)! Otherwise, the program won't run properly! The source code is available here.