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Copy Number Studies in Noisy Samples
AbstractSystem noise was analyzed in 77 Affymetrix 6.0 samples from a previous clinical study of copy number variation (CNV). Twenty-three samples were classified as eligible for CNV detection, 29 samples as ineligible and 25 were classified as being of intermediate quality. New software (“noise-free-cnv”) was developed to visualize the data and reduce system noise. Fresh DNA preparations were more likely to yield eligible samples (p < 0.001). Eligible samples had higher rates of successfully genotyped SNPs (p < 0.001) and lower variance of signal intensities (p < 0.001), yielded fewer CNV findings after Birdview analysis (p < 0.001), and showed a tendency to yield fewer PennCNV calls (p = 0.053). The noise-free-cnv software visualized trend patterns of noise in the signal intensities across the ordered SNPs, including a wave pattern of noise, being co-linear with the banding pattern of metaphase chromosomes, as well as system deviations of individual probe sets (per-SNP noise). Wave noise and per-SNP noise occurred independently and could be separately removed from the samples. We recommend a two-step procedure of CNV validation, including noise reduction and visual inspection of all CNV calls, prior to molecular validation of a selected number of putative CNVs.
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Ginsbach, P.; Chen, B.; Jiang, Y.; Engelter, S.T.; Grond-Ginsbach, C. Copy Number Studies in Noisy Samples. Microarrays 2013, 2, 284-303.View more citation formats
Ginsbach P, Chen B, Jiang Y, Engelter ST, Grond-Ginsbach C. Copy Number Studies in Noisy Samples. Microarrays. 2013; 2(4):284-303.Chicago/Turabian Style
Ginsbach, Philip; Chen, Bowang; Jiang, Yanxiang; Engelter, Stefan T.; Grond-Ginsbach, Caspar. 2013. "Copy Number Studies in Noisy Samples." Microarrays 2, no. 4: 284-303.