Ben Chun Liu, 38, was arrested Friday for allegedly poisoning the drink of Mei Cao, UCSF spokeswoman Kristen Bole said.
Both work in the university's urology department. Bole said she did not know whether the two had any sort of relationship outside of work.
Liu is a Chinese citizen and is in the United States on a work visa. He has been placed on an immigration hold and was still in custody in San Francisco County jail on Monday, Bole said.
Bole said police had searched both the urology lab and Liu's San Francisco home and recovered evidence of the crime, but she did not know whether the alleged poisoning occurred on the university campus.
Cao was examined at the UCSF Medical Center and was later released. Bole said that because of the ongoing investigation, she could not say what substance was used to allegedly poison the drink.
Police are still investigating the motive but Bole said it does not appear there are additional suspects or victims in the case.