Shamim M, Baig M, Nataraju B, Datta R K, Gupta S K
Gamete Antigen Laboratory, National Institute of Immunology, New Delhi, India.
J Immunoassay. 1995 May;16(2):155-66. doi: 10.1080/15321819508013555.
The symptomology of BmNPV infection in Bombyx mori L depends on the stages of infection. Discernible symptoms develop at later stages of infection, which leads to improper diagnosis and poor crop yield with sericulturists. In the present study development of direct and protein-A linked monoclonal antibody latex (PALMAL) agglutination test for the detection of BmNPV infection in silkworm is described. Latex beads were precoated with protein-A and then sensitised with monoclonal antibody MA-231 (125 micrograms/ml). PALMAL test could detect 1 x 10(5) nuclear polyhedra/test and is ten times more sensitive than the direct agglutination test employing purified polyclonal antibodies. No agglutination was observed in presence of B. thuringiensis, S. marcescens, N. bombycis, group-A streptococci, Staphylococcus aureus, E. coli and normal haemolymph protein indicating the specificity of the test. Fifty haemolymph samples 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 > or = 5 x 10(6) BmNPV/ml showed positive agglutination. However, 4 samples having < 5 x 10(6) BmNPV/ml failed to show positive agglutination thereby indicating the limit of sensitivity of the assay.
家蚕感染家蚕核型多角体病毒（BmNPV）的症状取决于感染阶段。在感染后期才会出现明显症状，这导致养蚕者诊断不当，蚕茧产量降低。本研究描述了用于检测家蚕中BmNPV感染的直接和蛋白A连接单克隆抗体乳胶（PALMAL）凝集试验的开发。用蛋白A预包被乳胶珠，然后用单克隆抗体MA - 231（125微克/毫升）致敏。PALMAL试验可检测到1×10⁵个核多角体/试验，比使用纯化多克隆抗体的直接凝集试验灵敏十倍。在苏云金芽孢杆菌、粘质沙雷氏菌、家蚕微孢子虫、A组链球菌、金黄色葡萄球菌、大肠杆菌和正常血淋巴蛋白存在的情况下未观察到凝集，表明该试验具有特异性。通过PALMAL试验对从田间采集的50份血淋巴样本进行了评估。21份感染非BmNPV的样本未显示阳性凝集。25份BmNPV含量≥5×10⁶/毫升的样本显示阳性凝集。然而，4份BmNPV含量＜5×10⁶/毫升的样本未显示阳性凝集，从而表明了该检测方法的灵敏度极限。
