Figure 1
From: Combining gene expression data from different generations of oligonucleotide arrays
A schematic view of the procedure. The same RNA was hybridized on both HG-U95Av2 and HG-U133A arrays, for 14 samples. Three methods for matching the probes were considered, but the two datasets gave highly inconsistent results in cluster analysis and identification of differentially expressed genes. To improve the comparability in general, probe-level sequence information was exploited. All 25-mer probes were aligned to human genome sequences by BLAT and then filtered based on the length of their overlap with the probes on the other array. New expression indices were calculated using only the selected probes, and this results in higher reproducibility.