scFISH on human metaphase chromosomes stained with 4‘,6-diamidino-2-phenylindole (DAPI). Probes are labeled with digoxigenin-dUTP and detected with rhodamine-conjugated antibody to digoxigenin. Hybridized chromosomes are indicated by arrows. PanelsA and B show chromosome 15q11.2–specific hybridization of the 3544-bp MAGEL2 probe with (A) and without (B) preannealing with Cot1 DNA. No differences in the respective hybridization patterns are observed. Panels C and D indicate hybridization of chromosome 1p36–specific CDC2L1 probes in the absence of Cot1 DNA. The 4823-bp probe is shown in panel C, and the combined 4823-bp and 4724-bp probes are shown in panel D. Chromosome 1 homologs in both panels show a single region of hybridization. Panels E and F show hybridization of chromosome 22q11.2 HIRA probes (combined 2848-bp, 3344-bp, 3691-bp, and 5170-bp fragments) on cells from a normal individual (E) and an individual with DiGeorge syndrome (F). Panel F shows a hemizygous chromosome 22q11.2 deletion (*).
