Nuclear localization of the IGH locus in relation to the chromosome 14 territory. Ideograms showing the probe combination depicts 14WCP in red and the IGH probe in green in lymphocytes and Pfeiffer cells ((A,D), respectively). Examples of lymphocyte nuclei showing WCP14/IGH hybridization in lymphocytes and Pfeiffer cells. In the Pfeiffer nuclei der(18) is indicated. Der(14) is not indicated due to being not distinguishable from the normal chromosome 14 ((B,E), respectively). Schematic representations of the FISH patterns observed, with the different proportions of nuclei with signals, from left to right, specific for both alleles within the chromosome territory, one allele within the chromosome territory, or both alleles looping out of the chromosome territory ((C,F), respectively).