Introduction
IGB can be used to visualize data from Affymetrix showing the locations of GeneChip Expression Array probe sets and target sequences aligned to a genome.
In most Affymetrix arrays, probes are grouped conceptually into probe sets, groups of probes that are expected to measure expression for individual known or computationally-deduced mRNA molecules.
These target sequences may be identical to known mRNA sequences in GenBank, or they may have been produced computationally by merging ESTs or mRNA sequences into a single sequence, sometimes called a "consensus" sequence.
IGB can be used to visualize the location of design sequences and probes within the genomic sequence. Probe set alignments are available under the IGB QuickLoad DAS2 data source in IGB.