Establishment of Nucleic Acid Amplification Technology for the Detection of Mycoplasma in Biological Products

Currently, the most commonly used methods for detecting Mycoplasma are the culture method and the indicator cell culture method. However, both approaches exhibit low sensitivity and are incapable of detecting low-concentration contamination. In addition, the detection period may extend up to 28 days, which is unsuitable for rapid screening and may delay timely contamination control measures. To address these limitations, a Mycoplasma detection method based on nucleic acid amplification technology (NAT) was developed following a comparative analysis of gene sequences from various Mycoplasma species. The method was validated with respect to its detection performance and its applicability to biological product samples. DNA was extracted from Mycoplasma-contaminated samples using a magnetic bead-based nucleic acid extraction method. Universal primers were designed based on the highly conserved 16S rRNA gene sequence of Mycoplasma, and amplification was performed using multiplex quantitative PCR (qPCR) with fluorescent probes. The limit of detection (LOD) was established based on statistics of 24 replicates. Method specificity and robustness were evaluated according to the guidelines set by the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH Q2), while sample applicability was assessed in accordance with the European Pharmacopoeia (EP) <2.6.7>. The NAT-based Mycoplasma detection method enabled rapid, qualitative identification of Mycoplasma contamination. The validated LOD was 10 CFU/mL, and the method met predefined requirements for sensitivity, specificity, and robustness. To assess applicability, real biological product samples, including monoclonal antibodies, antibody fusion proteins, bispecific antibodies, and trispecific antibodies, were spiked with 10 CFU/mL of standard Mycoplasma strains. All spiked samples tested positive. These findings confirm that the NAT-based Mycoplasma detection method is suitable for process control and product release testing in the production of biological products.