Sumner's research interests include the development, advancement and implementation of leading-edge instrumental techniques for large scale profiling and identification of the functional products of gene expression, namely proteins and metabolites. Profiling large numbers of proteins (proteomics) and large numbers of metabolites (metabolomics) provides a high-resolution view of the biochemical phenotype. Comparative profiling provides detailed quantitative and qualitative information that is proving to be highly valuable in gene validation, gene discovery, elucidation of pathway mechanisms and providing insight into the cellular response of an organism to external stimuli. Correlation of the expression profiles with genetic information also provides a unique way of understanding gene function and interrelationships between genes. The task of profiling large numbers of proteins and metabolites simultaneously is still quite challenging. Sumner's lab is approaching these challenges using mass spectrometry (MS) coupled with advanced separation technologies. Information obtained from these experiments is very specific and highly useful in chemical identification and characterization.