Fig. 6. Two-color FISH showing the loop configuration changes of a 300 kb genomic region. (A) The V-shaped configuration of both red and green color probes were anchored on the nuclear matrix. (B,C) The linear-shaped configuration with only one probe (red or green) anchored on the nuclear matrix whereas the adjacent probe was not anchored on the matrix. The explanation for the configuration changes is that the anchor was not fixed.