DIFFERENCES IN PARTICLE STABILITY AND ELECTROPHORETIC BEHAVIOUR AMONG TOMATO ASPERMY VIRUS ISOLATES

For serological and immunoelectrophoretic studies the isolates were purified by methods earlier described. Use of phosphate buffer for extraction and HCl to precipitate normal proteins, effective in the purification of the isolates Y7 and H, was not suitable for isolate NZ. However, the NZ isolate was well purified by another method using citrate buffer for extraction; this procedure was found equally suitable for isolates Y7 and H. Serological assays showed that the particles of the NZ isolate tend to degrade quickly and are less stable than those of the other two isolates.

In double diffusion serological tests, no differences among the isolates were detected. Based on the present study and earlier data minor differences were found in the charge on the particles of individual TAV isolates, but no correlation between the charge and stability could be observed.