Flow Cytometry Immunophenotyping in Cell Therapy: A Practical Guide
Cell therapy products are, quite literally, made of cells — which means proving what those cells actually are is one of the most fundamental steps in demonstrating product identity, purity, and safety. That's where flow cytometry immunophenotyping comes in. It's one of the most widely used analytical techniques in cell therapy development, and understanding how it works — and where it fits into your testing strategy — matters for anyone bringing a cell therapy product toward the clinic. What Is Flow Cytometry Immunophenotyping? Flow cytometry immunophenotyping is a technique used to identify and characterize cell populations based on the surface and intracellular markers they express. Cells are labeled with fluorescently tagged antibodies that bind to specific proteins — such as CD3, CD4, CD8, CD19, or CD56, depending on the therapy — and then passed single-file through a laser-based detection system. As each cell passes through, the instrument measures the fluorescence and ...