Figure 1: Identification of the common counts as basis for the calculation of the cross-over value. The matrices for the NC (a) and TEST (b) result from an experiment with 4 counts () and a single cross-over from fluorochrome B in detector DA. The matching rows of the NC and TEST matrices (grey) are defined as the matrix of the Common Counts (c). The rows in the Common Counts define counts with zero primary fluorescence for fluorochrome (). The cross-over value from fluorochrome B in DA can be calculated directly from the common counts. In the case as shown, 40/800 = 0.05 and 20/400 = 0.05.