As of late 2025, the rise of Advanced Therapy Medicinal Products (ATMPs) has necessitated a shift in the bioanalytical capabilities of preclinical CROs. Unlike traditional small molecules, cell and gene therapies require specialized assays to monitor Vector Shedding, Biodistribution, and Transgene Expression. CROs have integrated droplet digital PCR (ddPCR) and next-generation sequencing (NGS) to quantify viral vector copies within various tissues with sub-picogram sensitivity.

A major focus in this segment is the assessment of "Immunogenicity" and the potential for cytokine release syndrome (CRS). Preclinical labs now utilize humanized mouse models and in vitro human cytokine-storm assays to predict how a patient’s immune system might react to a genomic payload. For a technical analysis of the regulatory requirements for long-term "Persistence Studies" in gene therapy, the Preclinical CRO Market resource provides a detailed look at the safety protocols. These complex workflows are essential for mitigating the risks of off-target effects and ensuring the durable expression of the therapeutic protein in target cells.