Evaluation of an ATP-Bioluminescence Rapid Microbial Screening Method for In-Process Biologics

This study compared an adenosine triphosphate (ATP)-based bioluminescence rapid microbial method (RMM) with a conventional sterility method for biologics sample testing. The RMM is based on a comparison of ATP levels in inoculated and uninoculated microbiological growth medium samples following growth enrichment incubation. The biologics samples qualified in this study were recombinant monoclonal antibodies and hybridoma cell culture supernatants. Initially, the lot-to-lot variation in background ATP of these samples posed significant challenges. Two strategies to increase the signal-to-noise ratio (positive result/background ATP) were evaluated: enzyme-based signal amplification and reduction of the broth-based noise through broth selection. Following qualification of the RMM for antibody and cell culture samples, the RMM was also utilized for rapid screening of several sources of purified water. This ATP-based RMM has proved invaluable in routine testing of diverse biologics samples at our discovery research site and plays a key role in the investigation of contaminated samples.LAY ABSTRACT: Biologics research laboratories routinely conduct sterility testing of products in development. However, the lengthy turnaround time for detection of microbial contaminants when using a conventional sterility test is a bottleneck in this fast-paced environment. This study investigated an adenosine triphosphate-based bioluminescence rapid microbial method (RMM) for biologics samples, including monoclonal antibodies and hybridoma cell cultures. The results showed that the RMM allowed detection of antibody sample contaminants after only three days of incubation. In addition to being faster than the standard method, the RMM proved more reliable in detecting contaminants in cell culture samples with antibiotics. Since its initial evaluation, this RMM has accelerated biologics sterility testing across multiple projects at our site.