Project description:Affymetrix U133 Plus 2.0 arrays were hybridized with varying amounts of starting material to determine whether different measurements of gene expression were observed. Keywords: Affymetrix starting material study
Project description:RNA from the same tumor sample (n=98) was also processed using the 3' IVT kit (Affymetrix) and hybridized to U133 Plus 2.0 arrays (Affymetrix).
Project description:Gene expression profiling of normal hematopoietic cell subpopulations RNA extracted from flow sorted normal hematopietic cells were hybridized onto Affymetrix U133 Plus 2.0 arrays.
Project description:Affymetrix U133 Plus 2.0 arrays were hybridized with varying amounts of starting material to determine whether different measurements of gene expression were observed. Experiment Overall Design: 1 ug, 2, ug, 5, and 10 ug of Stratagene universal human reference RNA was used to setup a series of reactions which were subsequently hybridized to Affymetrix U133 Plus 2.0 arrays. 1 ug samples were performed in triplicate and the entire experiement was repeated. BACKGROUND: There are many potential sources of variability in a microarray experiment. Variation can arise from many aspects of the collection and processing of samples for gene expression analysis. Oligonucleotide-based arrays are thought to minimize one source of variability as identical oligonucleotides are expected to recognize the same transcripts during hybridization. RESULTS: We demonstrate that although the probes on the U133A GeneChip arrays are identical in sequence to probes designed for the U133 Plus 2.0 arrays the values obtained from an experimental hybridization can be quite different. Nearly half of the probesets in common between the two array types can produce slightly different values from the same sample. Nearly 70% of the individual probes in these probesets produced array specific differences. CONCLUSION: The context of the probe may also contribute some bias to the final measured value of gene expression. At a minimum, this should add an extra level of caution when considering the direct comparison of experiments performed in two microarray formats. More importantly, this suggests that it may not be possible to know which value is the most accurate representation of a biological sample when comparing two formats.
Project description:1. Keratinocytes infected with retroviruses expressing control or SNAI2 shRNAs were cultured in growth medium and Affymetrix HG-U133 plus 2.0 arrays were used to determine global gene expression profiles. 2. Keratinocytes infected with retroviruses overexpressing LACZ or SNAI2 were cultured in growth medium and Affymetrix HG-U133 plus 2.0 arrays were used to determine global gene expression profiles.
Project description:The primary goal of this study was to compare the performances of Rhesus Macaque Genome Array and Human Genome U133 Plus 2.0 Array with respect to the detection of differential expressions when rhesus macaque RNA extracts were labeled and hybridized. The secondary goal of this study was to investigate the effect of mismatch position on signal strength in Affymetrix GeneChips by examining naturally occurring mismatches between rhesus macaque transcripts and human probes from Human Genome U133 Plus 2.0 Array. The primary goal of this study was to compare the performances of Rhesus Macaque Genome Array and Human Genome U133 Plus 2.0 Array with respect to the detection of differential expressions when rhesus macaque RNA extracts were labeled and hybridized. The secondary goal of this study was to investigate the effect of mismatch position on signal strength in Affymetrix GeneChips by examining naturally occurring mismatches between rhesus macaque transcripts and human probes from Human Genome U133 Plus 2.0 Array. Keywords: cross hybridization
Project description:Samples were prospectively collected during colonoscopic examination from 46 rectal cancer patients before starting preoperative chemoradiotherapy. The expression profiles were determined using Affymetrix Human Genome U133 Plus 2.0 arrays. Comparison between the sample groups allow to identify a set of discriminating genes that can be used for prediction of the response to radiotherapy in rectal cancer.
Project description:Four vehicle-treated and four HhAntag-treated pancreatic xenograft tumors were profiled for gene expression changes using Affymetrix U133 Plus 2.0 and Affymetrix Mouse Genome 430 2.0 arrays. Keywords: comparative gene expression, hedgehog, hh
