The IP is an innovative approach in cellular therapy safety assurance. It addresses concerns regarding residual feeder cells in therapeutic immune cell products, which may pose risks such as unregulated immune activation and proliferation. Leveraging the unique attributes of the K562 cell line, commonly used as a base for feeder cells, the assay utilizes quantitative PCR (qPCR) targeting specific markers like BCR-ABL or transgenes for sensitive and rapid detection of residual feeder cell contamination. This method offers higher sensitivity and faster results compared to existing assays and leverages clinically-validated qPCR techniques for enhanced safety screening. Development has reached the proof of principle/prototype stage and is poised to address critical safety concerns in cellular therapy manufacturing. The assay’s potential applications span across the cellular therapy landscape.