Arjun Raj

Arjun Raj is a Professor of Bioengineering in the School of Engineering and Applied Sciences and Professor of Genetics in the Perelman School of Medicine at the University of Pennsylvania. He holds the Richard K. Lubin Professorship and leads a research laboratory focused on quantitative molecular biology, particularly single-cell gene expression variability and its implications in cancer and development.

His research interests include chromosome structure and gene expression, non-coding RNA, and global regulation of gene expression. The lab has pioneered quantitative single-molecule RNA detection techniques, such as RNA FISH, to study transcriptional bursting and cell-to-cell variability. Applications of this work span cancer biology, stem cell research, and developmental genetics.

Recent publications (2023-2025) highlight a strong emphasis on spatial transcriptomics, lineage tracing, and therapy resistance in cancer. Key findings involve nuclear speckle regulation, innate immune memory, and the development of rapid diagnostic tools. The lab's interdisciplinary approach bridges fundamental mechanisms with clinical applications in melanoma and infectious diseases.

Scientific Honors:

• Richard K. Lubin Professorship

Professor Raj mentors a diverse group of students, including PhD candidates Miles Arnett and Gianna Busch, MD/PhD students Vinay Ayyappan, Ryan Boe, and Jessica Li, and undergraduate Caitlin Fagan. His lab fosters collaboration across biology, engineering, and clinical medicine to solve complex problems in cellular function.

The Raj Lab, based in the Clinical Research Building, develops innovative tools like ClampFISH for amplified RNA detection and maintains an open-science ethos through shared resources. Their work on single-cell variability has led to significant insights into cancer drug resistance and developmental robustness.