Lay Harn was appointed as a professor by Universiti Sains Malaysia since 2001. She is now heading the Pharmaceutical Department of School of Pharmaceutical Sciences. She was the former deputy director of Dopint Control Centre, and has been appointment as the expert panel for R,D&C grant by Ministry of Science, Technology and Innovation Malaysia. Programme Coordinator for Toxicology Laboratory of National Poison Centre, Malaysia. Research Fello of National Institute of Phamarceutical and Nutraceutical Malaysia. Her research field is in proteomic study, she has patented her innovations on the urinary biomarker for diagnosis of kidney stone disease and protein biomarkers for differentiation of the source of gelatin either as halal or non-halal locally and internationally. Other research findings on the biomarkers potentially use as drug target and plant based useful proteins for industrial and medicinals have been published in peer reviewed publications. Besides being actively involved in research and innovation, she has also edited 5 books on cancer therapy and food suitable for cancer patients for the use of general public.

Her research field is in proteomic study, she has patented her innovations on the urinary biomarker for diagnosis of kidney stone disease and protein biomarkers for differentiation of the source of gelatin either as halal or non-halal locally and internationally. Other research findings on the biomarkers potentially use as drug target and plant based useful proteins for industrial and medicinals have been published in peer reviewed publications.