Produksi dan Evaluasi Antibodi Poliklonal untuk Deteksi Toksin Photorhabdus spp.

Production and Evaluation of Polyclonal Antibody for Detection of Photorhabdus spp. Toxin. Yadi Suryadi, Ifa Manzila, Alina Akhdiya, and Etty Pratiwi. The research was aimed to produce and evaluate polyclonal antibody (PAb) for specific Photorhabdus spp. bacterial toxin detection. Photorhabdus spp. toxin of HJ isolates which was purified using Hi Prep. 16/60 Sephacryl S-200 HR column chromatography revealed three different peaks of polypeptides. The results showed that the protein concentration of crude antigen protein (supernatant) was 3,711 μg/μl, whilst fraction of protein was 1,95 x 10-2 μg/μl, respectively. The bioassay using Tenebrio molitor larvae-3 indicated that after 48 h application, the percentage of larvae mortality by crude antigen was lower (73%) than by fraction antigen (93%). Based upon NCM-ELISA test, PAb of fraction protein derived from HJ isolate reacted with Photorhabdus spp. antigen yielded stronger or darker violet color on membrane than that of crude protein. In addition, it was observed that PAb could differentiate specifically Photorhabdus spp. toxin with other bacterial filtrate such as Xanthomonas oryzae pv oryzae, X. campestris pv glycinea, Ralstonia solanacearum, Pseudomonas syringae pv glycinea and P. fluorescens, however it showed cross reaction with Escherichia coli. Further tests are needed in optimizing PAb-Photorhabdus spp. sensitivity to achieve effective concentration for detection of Photorhabdus spp. toxin as well as specificity test against other bacterial antigens.