us host cell protein testing market is projected to grow from USD 233.54 million in 2025 to USD 409.33 million by 2035, registering a CAGR of 5.77%. The market was estimated at USD 220.8 million in 2024, with rising biopharmaceutical demand and regulatory requirements supporting expansion.

Technological advancements are improving the accuracy and efficiency of host cell protein testing. Mass spectrometry, chromatography, automation, and high-throughput screening are being adopted to improve detection, quantification, and laboratory productivity.

PCR-based assays hold the largest position among testing types, supported by their accuracy, sensitivity, and suitability for high-throughput applications. ELISA-based assays are identified as the fastest-growing segment because of their ease of use, adaptability, and cost-effectiveness.

Biopharmaceutical companies represent the largest end-user segment, while contract research organizations are the fastest-growing category. Increasing outsourcing of research activities and demand for specialized testing services are creating additional opportunities for CROs in the United States.