The rise of Advanced Therapy Medicinal Products (ATMPs), such as CAR-T cell therapies and gene vectors, has created a need for highly specialized analytical testing that traditional labs cannot provide. These therapies require complex assays for Vector Copy Number (VCN), Infectious Titer, and Cell Viability. Unlike small-molecule drugs, these products are living biological entities, meaning the testing must be conducted with extreme speed and precision.

Outsourcing is particularly prevalent in the CGT sector because of the "multi-modal" nature of the testing required. A single gene therapy product may require molecular biology (PCR), protein analysis (ELISA), and flow cytometry all within the same testing window. Insights into the specialized "Centers of Excellence" serving the CGT sector can be found in the Pharmaceutical Analytical Testing Outsourcing Market documentation. These labs often operate under "enhanced GMP" standards to handle the unique biosafety risks associated with viral vectors.

Another critical component of CGT testing is Potency Assays. Because these drugs often have complex mechanisms of action, the lab must develop a biological assay that proves the drug actually works in a living system. These "cell-based assays" are notoriously difficult to validate and require a high degree of technical expertise. By outsourcing to a specialized CGT lab, developers can ensure that their potency methods meet the rigorous standards required for late-phase clinical trials and commercial approval.