What is a probe set? What do the different suffixes attached to a probe set name mean?
According to Affymetrix.com: A probe set is a collection of probes designed to interrogate a given sequence. A probe set name is used to refer to a probe set, which looks like the following: 12345_at or 12345_a_at or 12345_s_at or 12345_x_at The last three characters (_at) identify the probe set strand. Probe sets that are designed to detect the anti-sense strand of the gene of interest are annotated with “_at”. There are different types of probe sets that can result from the probe selection process. Most probe sets have an extension of an underscore and a letter to designate the probe set type, except for unique probe sets. These different probe set types are shown in the example above between the underscores (The first example does not have a probe set). Probes in a gene family probe set (_a set) all cross-hybridize to the same set of sequences that belong to the same gene family (i.e. having same name in the “geneCluster” column). This probe set type is only created if the “geneClus
