Electronic Supplementary Materials (ESI) Q-GDEMAR: A METHOD FOR THE IDENTIFICATION OF DIFFERENTIALLY EXPRESSED GENES IN MICROARRAYS WITH UNBALANCED GROUPS

c. Determine the quantiles (Q) associated to the following series of cumulated relative frequencies: 1x10, 1x10, 1x10, 1x10, 1x10, 0.25, 0.5, 0.75, 0.99, 0.999, 0.9999, 0.99999, 0.999999). To this aim we used the program Matlab v.7.10 (Mathworks, USA). Although “relative frequencies” and “probabilities” are different mathematical entities (i.e., probabilities are the asymptotic limit of the relative frequencies when the number of replications tend to infinity), herein we treat both concepts as equivalents given the great number of genes tested in the microarray. Note that quantiles Q0.25 and Q0.75 are of interest to determine the Inter-Quartile Range (IQR; IQR=Q0.75-Q0.25). The quantile Q0.50 is the median value of the distribution.