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Development of a vaccine to limit the impact of antibiotic resistant <i>Neisseria gonorrhoeae</i> is now a global priority. Serum bactericidal antibody (SBA) is a possible indicator of protective immunity to <i>N. gonorrhoeae</i>, but conventional assays measure colony forming units (CFU), which is time-consuming. A luminescent assay that quantifies ATP as a surrogate measure of bacterial viability was tested on <i>N. gonorrhoeae</i> strains FA1090, MS11 and P9-17 and compared to CFU-based readouts. There was a linear relationship between CFU and ATP levels for all three strains (<i>r </i>&gt; 0.9). Normal human serum (NHS) is a common source of complement for SBA assays, but needs to be screened for non-specific bactericidal activity. NHS from 10 individuals were used for serum sensitivity assays&#8212;sensitivity values were significantly reduced with the ATP method for FA1090 (5/10, <i>p</i> &lt; 0.05) and MS11 (10/10, <i>p</i> &lt; 0.05), whereas P9-17 data were comparable for all donors. Our results suggest that measuring ATP underestimates serum sensitivity of <i>N. gonorrhoeae</i> and that the CFU method is a better approach. However, mouse anti-P9-17 outer membrane vesicles (OMV) SBA titres to P9-17 were comparable with both methods (<i>r </i>= 0.97), suggesting this assay can be used to rapidly screen sera for bactericidal antibodies to gonococci.