Applications of functional gene microarrays for profiling microbial communities

► Functional gene arrays (FGAs) target key microbial functional processes in the environment. ► Details of FGA operations including target preparation, hybridization, and data analysis. ► FGAs can address basic scientific questions and link communities to ecosystem functioning. ► Examples of FGAs for analyzing microbial communities from different habitats. ► Discussion on challenges and future directions in FGA applications.