Genomic DNA was extracted from hepatocellular carcinoma and their adjacent liver tissues using the Qiagen DNA Blood Mini Kit. DNA quality and quantity was assessed using a Nanodrop Spectrophotometer and agarose gel electrophoresis.
Label
Biotin
Label protocol
As per manufacturer (Affymetrix)
Hybridization protocol
DNA was restriction digested, PCR amplified, fragmented, labeled and hybridized to each array according to the manufacturer's instructions.
Scan protocol
The Arrays were then washed using Affymetrix fluidics stations, and scanned using the Gene Chip Scanner 3000.
Description
Hybridized to 250K_Sty
Data processing
The array image was acquired using Affymetrix GeneChip® Operating Software (GCOS version 1.4). Copy number values for individual SNPs were extracted and converted from CEL files into signal intensities using GTYPE 4.1 and Affymetrix Copy Number Analysis Tool (CNAT 4.0.1) softwares. Genomic Smoothing analysis was performed by using the smoothing window of 0 Mb, and inferred copy number states were derived from a Hidden Markov Model (HMM) based algorithm implemented in CNAT 4.0.1. Circular Binary Segmentation (Ohlsen et al., 2004) was applied using DNAcopy package for R Bioconductor on raw data.
