YSI

YSI is an analytical instrumentation company best known for biosensors, biochemistry analyzers, and water-quality measurement systems. Historically founded as Yellow Springs Instrument Company, YSI has a long presence in life sciences through enzyme-electrode analyzers used in clinical, biopharma, and research settings, including glucose and metabolite measurement. The company also has a larger environmental monitoring business spanning water quality sondes, sampling systems, and field instrumentation. YSI has been part of Xylem since 2011 and operates as a brand within Xylem Analytics rather than as an independent therapeutic biotech company. Its healthcare relevance is primarily in life science tools and diagnostic/measurement instrumentation, not drug development.