Located on the University of California, Davis campus, in the Department of Plant Sciences, the Stable Isotope Facility (SIF) provides analytical services for local, national, and international researchers. The SIF analyzes over 190,000 samples every year on 16 analytical systems.

The SIF offers analysis for stable isotopes of several light elements, including H, C, N, O, and S, in a wide variety of sample forms at natural abundance or tracer levels by continuous-flow Isotope-Ratio Mass Spectrometry (IRMS). The following analyses are available:

• C, N, and S in solid samples, such as soils, plant materials, and dried extracts (combustion)
• H and O in solid organic samples (pyrolysis)
• Atmospheric gases, including CH₄, CO₂, N₂, N₂O, and O₂
• Compound-specific isotope analysis using GC-C-IRMS
• H and O in water, including enriched or small samples
• Dissolved inorganic and organic carbon in water or extracts
• N and O of nitrate in natural waters
• C and O of biogenic carbonate or apatite

The SIF strives to provide cutting edge technologies in stable isotope analysis. To achieve this goal, the SIF collaborates with researchers worldwide to develop new analytical methods and applications of stable isotopes in new areas of research.