Patent ID: 7267947

Claim:
A method of screening for the presence of breast cancer cells that have an increase in copy number of a target polynucleotide on chromosome 20 in a sample, the method comprising: contacting a nucleic acid sample from a human patient with a probe which binds selectively under hybridization conditions comprising 50% formamide, 2×SSC at 37° C. and wash conditions comprising 50% formamide, 2×SSC at 45° C. for 10 minutes to a target polynucleotide sequence on a region of chromosome 20 in which copy number is altered in breast cancer cells wherein the probe binds selectively to the same target polynucleotide sequence as RMC20P100, RMC20P131, or RMC20P073, and is contacted with the sample under conditions in which the probe binds selectively with the target polynucleotide sequence to form a stable hybridization complex; and detecting the formation of a hybridization complex, thereby detecting breast cancer cells that have an increase in copy number of the target polynucleotide sequence.