P. SUVARNALATHA DEVI AND D. CHARITHA
Abstract
Monoclonal antibody Mab 7E12 (IgG2a) was developed against A. alternata. The antibody was capable of detecting A. alternata from cultures and in naturally infected groundnut leaf samples, by the technique monoclonal double antibody sandwich enzyme linked immunosorbent assay. Leaf extracts of healthy samples did not react and cross reactions with three other fungi isolated from groundnut were not observed. The specificity of the MAbs was tested using indirect enzyme linked immnuo-sorbent assay (ELISA) a.nd indirect competitive ELISA Cross reactivity was observed to some extent with A. tenuissima. A quantitative immuno assay was developed using an indirect competitive ELISA format that could detect as little as 4 ng of total protein (4 to 500 ng) and absorbance measured at 405 nm. The immunoassay accurately distinguished colonized from non-colonized plants and quantitatively differentiated the susceptible cultivar (TMV-2) from the resistant cultivar (Narayani). and hence control schedules are not yet developed for these diseases.