Objective To develop and validate a serum bactericidal assay(SBA)on Neisseria meningitides of serogroups A,C,W135 and Y. Methods Harvest time,preparation of target bacteria,reaction time and complement in SBA were optimized,based on which the quality control range of Men10 was determined. The optimized method was verified for specificity,linearity and precision. Results The bacteria were harvested when the A600 value reached 0. 5 ~ 0. 8. Frozen bacteria could be used as target bacteria instead of fresh bact...