Microarray technology is often used in gene expression exper- iments. Information retrieval in the context of microarrays has mainly been concerned with the analysis of the numeric data produced; how- ever, the experiments are often annotated with textual metadata. Al- though biomedical resources are exponentially growing, the text corpora are sparse and inconsistent in spite of attempts to standardize the format. Ordinary keyword search may in some cases be insucient to nd rele- vant information and the potential benet of using a semantic approach in this context has only been investigated to a limited degree. We explore the possibilities of retrieving biomedical information from microarrays in Gene Expression Omnibus (GEO), of which we have indexed a sample semantically, as a rst step towards ontology based searches. Through an example we argue that it is possible to improve the retrieval of biological information.