A dye swap merge is a replicate analysis which takes as input data from paired two-channel microarray assays where the sample labeled with one dye in the first assay is labeled with the other dye in the second assay and vice versa. The output for each reporter is obtained by combining its (raw or possibly pre-processed) M values in the two assays, where the M value in an assay is defined as the difference of the log intensities in the two channels. This can be used as a normalization step, when appropriate assumptions are met.