Joshua A. Welsh, Ph.D. is a Senior Staff Scientist in the Advanced Technology Group at Waters Biosciences, formerly BD Biosciences, in Milpitas, California. His work focuses on quantitative flow cytometry, flow cytometry standardization, small particle and extracellular vesicle analysis, and the development of tools and frameworks that improve reproducibility across instruments, sites, and assay contexts.
Dr. Welsh’s career has bridged academic, government, and industry research. Prior to joining industry, he worked at the U.S. National Institutes of Health, where his research focused on extracellular vesicle characterization and the standardization of small particle flow cytometry. He now leads next-generation standardization initiatives for the FACSDiscover platform within the Advanced Technology Group at Waters Biosciences.
A major focus of Dr. Welsh’s work has been the development of community standards, educational resources, and software tools for quantitative cytometry. He led the development of the MIFlowCyt-EV reporting framework and companion educational resources, and has contributed to broader extracellular vesicle standardization efforts including MISEV2023. He also developed FCMPASS, MPAPASS, and RPSPASS, software tools used internationally for flow cytometry calibration and small particle analysis.
Dr. Welsh has been an active contributor to ISAC and related societies for more than a decade. He was an ISAC Marylou Ingram Scholar from 2019 to 2023, serves on the ISAC Data Committee, and led the ISAC-ISEV-ISTH Extracellular Vesicle Flow Cytometry Working Group from 2016 to 2024. He has also served as an Associate Editor for Cytometry Part A and Current Protocols in Cytometry, contributed to CYTO tutorials and workshops, and delivered numerous invited talks and educational sessions.