Stein studied cellular and developmental biology at the University of Colorado Boulder.

She moved to Oregon State University for her doctoral research, where she studied the physiology of ammonia oxidising bacteria.

[1] Stein was a postdoctoral scholar at the Jet Propulsion Laboratory, where she built a mobile field lab to study biogenic gas fluxes in situ.

[7] The Haber-Bosch process, the main industrial procedure ammonia production, has dramatically impacted the Nitrogen cycle.

[8] In an effort to slow the runaway nitrogen cycle, Stein has proposed to replace chemical fertilisers with nitrification inhibitors.