Detection of single-copy differences. (A) Normal vs. normal hybridization of spleen DNA from a C57BL/6J female. (B) Comparative genomic hybridization of normal C57BL/6J female DNA vs. normal C57BL/6J male DNA. Plotted are log2-transformed hybridization ratios against the linear map position of the BACs (in Mb). Confidence levels were calculated according to the Rosetta Error Model. Red indicates significant gain in DNA copy number, green indicates significant loss, and black indicates no significant change. The CGH profile of the female vs. male hybridization shows identical DNA copy numbers for all autosomes (mean log2 ratio -0.0066, s.d. of the log2 ratios = 0.064); the copy numbers of male and female chromosome X sequences were clearly different (mean log2 ratio of 0.63).
