EVALUATION OF PROTEIN-A LINKED MONOCLONAL-ANTIBODY LATEX AGGLUTINATION-TEST FOR DIAGNOSIS OF NUCLEAR POLYHEDROSIS-VIRUS (BMNPV) OF SILKWORMBOMBYX-MORI L

The symptomology of BmNPV infection in Bombyx mori L depends on the st ages of infection. Discernible symptoms develop at later stages of inf ection, which leads to improper diagnosis and poor crop yield with ser iculturists. In the present study development of direct and protein-A linked monoclonal antibody latex (PALMAL) agglutination test for the d etection of BmNPV infection in silkworm is described. Latex beads were precoated with protein-A and then sensitised with monoclonal antibody MA-231 (125 mu g/ml). PALMAL test could detect 1X10(5) nuclear polyhe dra/test and is ten times more sensitive than the direct agglutination test employing purified polyclonal antibodies. No agglutination was o bserved in presence of B. thuringiensis, S. marcescens, N. bombycis, g roup-A streptococci, Staphylococcus aureus, E. coli and normal haemoly mph protein indicating the specificity of the test. Fifty haemolymph s amples collected from the field were evaluated by PALMAL test. Twenty one samples having infection other than BmNPV, failed to show positive agglutination. Twenty five samples having greater than or equal to 5X 10(6) BmNPV/ml showed positive agglutination. However, 4 samples havin g <5X10(6) BmNPV/ml failed to show positive agglutination thereby indi cating the limit of sensitivity of the assay.