Abstract
Microprecipitin method for serological reaction was modified by using multidish trays instead of petri-dishes. Multi-dish disposo trays (Linbro Chemical Co., Inc.) for tissue culture vessel with 96 holes (φ6mm) made by plastic, were used. Each 0.025ml of antigen and antiserum was mixed by semiautomatic pipettes (Micro selectapette; Clay Adams Co., Inc.). After mixing the mixtures by shaking the trays, paraffin oil (about 0.03ml) was added to prevent drying.
A dark field microscope was used to observe the reaction at magnification 16 or 25. Crude sap or purified preparations of five plant viruses, potato virus X, potato virus Y, potato virus S, cucumber green mottle mosaic virus and rice dwarf virus, were examined. The results indicated that this method was as sensitive as interface ring test. Advantage of this method is that very small amounts of antigen and antiserum are enough to detect the reaction, and one can handle easily many specimens in one tray. It was shown that serological reactions of PVX, PVY, PVS, CGMMV and RDV could be clearly observed and dilution end point of antiserum could be easily determined by this method under a dark field microscope.
