Nucleic acid microarrays are a rapidly expanding technology that enables the detection of pathogens at the genetic level. Currently, the processing of commercially produced microarrays requires cumbersome, expensive, and time-consuming benchtop equipment, which is not practical for point-of-care diagnostic applications. We demonstrate a portable module that can perform the hybridization, wash, and stain steps required for processing a nucleic acid microarray; and it performs these steps in a timeline significantly shorter than the standard commercial protocol. This device is automated, has a small footprint, and serves as a replacement for two commercial pieces of benchtop equipment. Furthermore, our device is designed to serve as a module in a portable biosensor that performs automated sample preparation and nucleic acid amplification. Results with Affymetrix GeneChips show that our device performs as well as non-portable equipment specifically manufactured to process these microarrays.