Researches Yuji Sekiguchi is doing a wide range of studies in the field of bio-measurement (1) to develop molecular methods and bioinfomatics for quantitative detection of particular nucleic acid sequences in sequence specific and/or highly multiplexed manners, (2) to develop techniques for measuring biological activities of cells, and (3) to develop techniques for quality control of high-throughput bio-measurements. Also, he is doing researches on microbial ecology, such as development of methods for cultivation of yet-to-be cultured microorganisms in environments, cultivation of yet-to-be cultivated microorganisms that are relevant to anoxic environments (such as animal gut and methanogenic wastewater treatment systems, community structure analysis of gut and other anoxic ecosystems, and syntrophism among anaerobic bacteria and methanogenic archaea.