What do the different statistics tell me for univariate comparison?
Several algorithms can be used to compare FACS data. The Kolmogorov-Smirnov (K-S) algorithm is a commonly used method to determine the confidence interval with which one can make the assertion that two flow cytometric univariate histograms are different. The Overton cumulative histogram subtraction algorithm essentially subtracts histograms on a channel-by-channel basis to provide a percent of positive cells. The Super-enhanced Dmax Subtraction (SED) is a new sophisticated algorithm by Bruce Bagwell to compute %Positives when comparing histograms. A new comparison algorithm was recently developed for the comparison of distributions, called Probability Binning (PB). The PB comparison is related to the Cox chi-square approach, but with modified binning such that it minimizes the maximal expected variance. This algorithm has been shown to detect small differences between two populations and it does so in a quantitative way. For more information, see the pages on Population Comparison.
