Meet our IVF & Andrology Lab Staff Members

Liesl Nel-Themaat, Ph.D., HCLD. (ABB)

Title: IVF Lab Director and Andrology/Endocrine Lab Director
Primary Location: Denver

Liesl Nel-Themaat, Ph.D., UC Denver ARM Senior Embryologist and Endocrinology Lab Supervisor

Dr. Liesl Nel-Themaat joined Advanced Reproductive Medicine in 2016. She is the IVF Lab Team Leader and Endocrine/Andrology Lab Director. She graduated with a Bachelor of Science from Stellenbosch University in South Africa and received her Ph.D. in assisted reproduction from Louisiana State University under Dr. Robert Godke. Her graduate studies focused on advanced reproductive technologies in endangered species at the Audubon Nature Institute in New Orleans.

After completing a postdoctoral fellowship studying post-implantation embryos at MD Anderson Cancer Center in Houston, TX, she worked as a clinical embryologist at Reproductive Biology Associates in Atlanta. She moved to Colorado in 2011 to work at Colorado Reproductive Endocrinology.

Dr. Nel-Themaat is involved in teaching fellows about reproductive lab sciences. She also participates in collaborative research and has published several original, peer reviewed research articles. Dr. Nel-Themaat is active on several local and national professional committees. She currently serves as the Supervisor Board Member and Chair of the Legislative Committee for the College of Reproductive Biology (CRB) and as the Vice President for the Society of Reproductive Biologists & Technologists. Dr. Nel-Themaat also co-founded and served as president of the Colorado Association of Reproductive Technologists for four years.

She enjoys an active, outdoors lifestyle with her husband and two children.

Melissa Rosario, B.A., T.S. (ABB)

Title: Senior Embryologist and Andrologist
Primary Location: Denver

Melissa Rosario | Advanced Reproductive MedicineMelissa has been working in the andrology and embryology laboratories at Advanced Reproductive Medicine since 2002. She has a Bachelor of Arts in Molecular Biology from Pomona College and spent 10 years pursuing academic research on multidrug resistance and pulmonary models of inflammation before switching to clinical duties. Melissa has been certified by the American Board of Bioanalysis (ABB) as a Technical Supervisor since 2007, and has been certified as a Reproductive Lab Inspector by the College of American Pathologists.

Melissa enjoys the active Colorado lifestyle and likes to learn new outdoor skills, such as tennis, scuba diving and triathlon training.

David Russell, B.S., T.S. (ABB)

Title: Embryologist and Andrologist
Primary Location: Denver

David RussellDavid received his Bachelor of Science in Biology from the University of New Mexico in 1987. He moved to Denver in 1989 and performed research at National Jewish Medical and Research Center and The University of Colorado Health Sciences Center. His research at NJMRC was in the field of immunology. He was also involved in the production of genetically engineered mice using targeted mutagenesis in mouse embryonic stem cells. David was recruited from National Jewish Medical Center in 2001 to work as a clinical embryologist at the University of Colorado. He is certified as a Technical Supervisor in Embryology and Andrology through the AAB.

Evelyn Llerena Cari, M.S.

Title: Health Care Professional 
Primary Location: Denver

Evelyn joined CU Advanced Reproductive Medicine (ARM) in July of 2015. She graduated with a Bachelor of Science from Universidad Nacional Mayor de San Marcos in Lima, Peru. During her studies, she completed a two-year internship at the Concebir IVF clinic. In graduate school she earned her Master in Science from University of Montreal in Quebec, Canada. She had a two-year focus in delayed implantation.

In 2013 she accepted a position at the University of Colorado as a professional research assistant. She originally started at the Cancer Center and has since transitioned to where her passion lies, at the OB-GYN department. Evelyn’s work at ARM has solidified her passion for reproductive technologies, and she continually strives to improve her skill set and knowledge under the guidance of her senior colleagues.

In her free time Evelyn enjoys running, snorkeling and hiking with her fiancé, Joe. She also continues a time honored Peruvian family tradition by cooking and baking for her friends.

Melissa Herb, RMA

Title: Lab Manager
Primary Location: Colorado Springs
Melissa HerbMelissa is a registered medical assistant (RMA) and has been with Advanced Reproductive Medicine since 2011. Most recently, Melissa serves as the manager of the Colorado Springs lab. She graduated with honors from Remington College and is registered with the American Medical Technologist Society. In her free time she enjoys the beautiful Colorado landscape while camping, snowboarding or riding dirt bikes with her husband.

Theresa Anderson, M.S.

Title: Andrologist
Primary Location: Denver

Theresa Anderson | CU ARM lab staffTheresa joined the CU ARM team in August 2017. She received her bachelor’s degree in Biomedical Science with a Neurobiology concentration in 2015 from Colorado State University, and completed her Master’s Degree in Assisted Reproductive Technologies in 2017. Her graduate studies focused on bovine and ovine reproduction, as well as the application of Assisted Reproduction in wildlife conservation.



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