We have assembled arrays of approximately 2,400 BAC clones for measurement
of DNA copy number across the human genome. The arrays provide precise meas
urement (s.d. of log(2) ratios=0.05-0.10) in cell lines and clinical materi
al, so that we can reliably detect and quantify high-level amplifications a
nd single-copy alterations in diploid, polyploid and heterogeneous backgrou
nds.