Stability of Spodoptera litura nucleopolyhedrovirus in sodium dodecyl sulphate

Sodium dodecyl sulfate (SDS) is a foaming agent used to extract occlusion bodies (OBs) of baculoviruses from infected cells or tissues of an insect. However, these OBs may be damaged by SDS at certain concentrations. In this study, the impact of different concentrations of SDS on OBs of Spodoptera litura nucleopolyhedrovirus (SpltNPV) was determined. Even though the number of OBs harvested increased with the increase in the concentration of SDS used in the extraction, the percentage of damaged OBs also increased correspondingly as detected through scanning electron microscope (SEM) photomicrographs. The result also indicates that infectivity of SpltNPV on second instars of S. litura larvae reduced significantly with an increase of SDS concentration used in the treatment. Among the four concentrations of SDS tested, SDS at 0.1% was able to release more quality virus. Thus, SDS of less than 0.1% is recommended for obtaining optimum number of quality OBs.