[1] Kleinman worked at National Institutes of Health (NIH) from 1975 to 2006 in the National Institute of Dental and Craniofacial Research (NIDCR) and served as Chief of the Cell Biology Section in NIDCR's Laboratory of Cell and Developmental Biology (1985–2006).

[1] Her laboratory was the first to report the wound-healing effects of thymosin beta 4 (TB4), a synthetic version of a naturally occurring molecule.

[1] Her research accomplishments also include defining various angiogenic and antiangiogenic molecules and identifying sites on laminin for adhesion, migration, neurite outgrowth, angiogenesis, metastases and inhibition of metastases, and the respective receptors.

[2] In 1992, during his first week as deputy director for intramural research, Lance Liotta appointed Kleinman to chair the new intramural women scientists' task force to investigate impediments to the advancement of women at NIH.

In 2006, she left the NIH to join the George Washington University as an adjunct professor in the department of biochemistry and molecular biology.