On July 3, 2025, PBL Assay Science lost one of our company's founders, Joan Pestka.
Joan Pestka co-founded PBL Assay Science in 1990 alongside her husband, Dr. Sidney Pestka. From the very beginning, Joan played an essential and hands-on role in building the company. While Dr. Pestka maintained his full-time academic responsibilities, Joan single-handedly managed every aspect of daily operations. Her responsibilities spanned purchasing, accounting, and collections; payroll, insurance, and employee benefits; human resources; product preparation, shipping, and receiving; as well as sales, customer service, and technical support.
Her dedication and guidance during these formative years laid the foundation for PBL’s values and long-term success. As the company grew and her son Robert Pestka joined the team a few years later, Joan was gradually able to delegate many of these duties, allowing her to guide the business through its next stages of development.
Prior to founding PBL, Joan taught high school mathematics and held research and administrative roles in the psychology departments of the University of Pennsylvania, American University, and George Washington University. She received a Master of Arts in Counseling Psychology from American University and a Bachelor of Arts in Mathematics from the University of Michigan, with minors in Psychology and Physics & Chemistry.
Joan was intensely interested in getting to know each of the hundreds of individuals who served PBL as employees during her 35 years at the company. She wanted to help them succeed professionally and was genuinely curious about their personal lives as well. And each employee recognized that Joan looked out for for each of them. With her keen insight and her training in clinical psychology, she never hesitated to offer professional and personal guidance when solicited—and sometimes when not solicited!
While she never had any formal education in medicine, her intuition combined with her 56-year marital partnership with a physician gave her surprising talent as an astute medical diagnostician. For years, after each of her diagnoses and recommendations proved correct, Joan would acknowledge these skills with the avowal “See, I should have gone to medical school!” As a result, her children finally capitulated and awarded her with an honorary Doctor of Medicine degree from fanciful Northern Caldwell University in 2011.
Joan played an outsized role in her family and with her PBL family. She supported her husband, raised her children, and attended to the needs of company employees at the same time, and each of these three parties came to rely upon her caring and compassion. Just as she did at home, Joan was determined to create a strong, close-knit community at PBL. She insisted on the importance of getting all employees together for multiple seasonal celebrations each year, where she could take pride in seeing the whole PBL family enjoying themselves together—Summer Event, Holiday Party, International Luncheon, and her personal favorite, Mister Softee Day. She dressed up as a witch on Halloween, and her Holiday Party speeches and songs were legendary.
Since her time as a teenager, Joan exuded presence of mind and comfortable self-assurance. She always knew who she was, and that strength of character underpinned her role as loving mother and caretaker of PBL. She channeled her self-assurance and will into compassion, and into supporting the people she cared about—whether those were family members, relatives, dear friends, or co-workers at PBL. Her impact will continue to resonate over the courses of our lives. We will miss her.
