Cell lines were grown according to standard conditions.
Extracted molecule
genomic DNA
Extraction protocol
DNA was obtained from cell line pellets or tumors frozen at the time of surgical dissection and maintained at -80C until use, with the exception of 11 gliomas from which sufficiently high-quality DNA could be obtained from paraffin-embedded samples. The majority of tumors were obtained at primary surgery, with the exceptions of 27 prostate tumors obtained through rapid autopsy programs at the Universities of Washington and Michigan
Label
Biotin
Label protocol
As per manufacturer (Affymetrix)
Hybridization protocol
Each sample was genotyped using the Sty I chip of the 500K Human Mapping Array wet (Affymetrix), containing probes to 238,270 SNP loci, according to manufacturer’s instructions. In brief, 250 ng of genomic DNA was digested with the StyI restriction enzyme (New England Biolabs), ligated to an adaptor with T4 ligase (New England Biolabs), and PCR-amplified using a 9700 Thermal Cycler I (Applied Biosystems) and Titanium Taq (Clontech) to achieve fragments ranging from 200-1100 bp. These fragments were pooled, concentrated, processed through a clean-up step, and further fragmented with DNaseI (Affymetrix) before being labeled, denatured, and hybridized to arrays
Scan protocol
Arrays were washed and scanned using the GeneChip Scanner 3000 7G (Affymetrix)
Description
Hybridized to 250K_Sty
Data processing
Probe-level signal intensities were normalized to a common reference array using quantile normalization and combined to form SNP-level signal intensities using the dChip model-based expression (PM/MM) method . Genome-wide copy number estimates were obtained using tangent normalization, in which tumor signal intensities are divided by signal intensities from the linear combination of all normal samples that is most similar to the tumor (as described in Beroukhim et al, In Press; and Getz et al., In Preparation). Cancer samples were normalized against a pool of 1,480 reference samples derived from multiple studies; the code and reference data necessary to replicate this analysis are available for download in GEO. Genotype Call (SNP call) are provided in .CHP.TXT files: AA, AB, BB, NC, and NoCall.
