Leslie Winkle is an experimental physicist at the California Institute of Technology who works in the same lab as Leonard. She is essentially his female counterpart, equipped with the same black framed glasses and zippered hoodies. Whenever depicted in the lab, she is always using the equipment inappropriately to prepare food, such as flash-freezing a banana with liquid nitrogen and then shattering it with a hammer to put in her cereal, or using a helium-neon laser to heat a cup of instant soup. She dates Leonard on-and-off, and later on Howard. When she insulted Sheldon's intelligence, he came to hate her, considering her one of his "archenemies."