GEO2R is an interactive web tool that allows users to compare two or more groups of Samples in a GEO Series in order to identify genes that are differentially expressed across experimental conditions. Results are presented as a table of genes ordered by significance.
GEO2R performs comparisons on original submitter-supplied processed data tables using the GEOquery and limma R packages from the Bioconductor project. Bioconductor is an open source software project based on the R programming language that provides tools for the analysis of high-throughput genomic data. The GEOquery R package parses GEO data into R data structures that can be used by other R packages. The limma (Linear Models for Microarray Analysis) R package has emerged as one of the most widely used statistical tests for identifying differentially expressed genes. It handles a wide range of experimental designs and data types and applies multiple-testing corrections on P-values to help correct for the occurrence of false positives. Thus, GEO2R provides a simple interface that allows users to perform R statistical analysis without command line expertise.
Unlike GEO's other DataSet analysis tools, GEO2R does not rely on curated DataSets and interrogates the original Series Matrix data file directly. This allows a greater proportion of GEO data to be analyzed in a timely manner. However, it is important to realize that this tool can access and analyze almost any GEO Series, regardless of data type and quality, so the user must be aware of GEO2R Limitations and caveats.