Comparative efficacy of different methods in the generation of 12S particles from 146S particles of FMDV serotype A and their detection using serotype (146S) specific monoclonal antibodies

Abstract

Foot-and-mouth disease [FMD] is a highly infectious and contagious viral disease of domestic and wild cloven hoofed animals. The disease is controlled by vaccination using inactivated vaccine as one of the important options. The integrity of 146S plays an important role in the efficacy of the vaccine. The currently applied methods like density gradient to check the integrity of the 146S particles are besotted with certain disadvantages. Therefore, we generated monoclonal antibodies (mAbs) specific to 146S of FMDV serotype A [Indian strain]. To test these mAbs for their specificity to 146S, conversion of 146S into 12S is a must. Normally, three methods like strong [1N HCl] and weak acid [Na2HPO4] methods; and heat method are followed in the conversion of 146S into 12S. Upon comparison of these methods in the present study, consistent results were obtained using heat method at 560C and 600C each for half an hour and one hour. However, the former two methods were very inconsistent in yielding 12S from 146S particle due to slight variation in the pH. Hence, we optimized heat method for efficient conversion of 146S particle to 12S particle of FMDV serotype A [A/INDIA/40/00], an Indian vaccine strain. The results are ascertained applying serotype specific [146S] monoclonal antibody based double antibody sandwich ELISA. However, the method needs to be evaluated using more number of 146S samples.