Teruka O'Connell, or Teri to her close friends, is an Asian-American woman, of Japanese and Irish heritage, in her late 20s-early 30s.  She stands 5'7" tall and has an athletic, if slightly thick build, from years practicing Shao Lin Kung Fu and Tae Kwon Do, and she wear spec over her brown eyes because of being myopic.  She is seen most often in a labcoat over business slacks and shirt, or tee-shirt and jeans because she has been working on her Doctoral thesis on Mutant Genetics, she can be seen in similar (minus the labcoat) casual attire or sweats when not at the laboratory in the hospital's research wing.
She is friendly, kind, if quiet and a little socially awkward when not discussing her many interests, particularly genetics, when she becomes more animated.  She seems to truly be herself when Jacob Davidovitch is around, having been best friends with him since middle school.  He is, in fact, her primary research subject, as well as herself.  She seems to have heightened intelligence, mental endurance, recall, and little need for sleep.
While Jacob has a had a crush on her for years, he knows that she is a lesbian.  She is currently dating a photojournalist, and it seems pretty serious, despite her travelling a lot.