RT Journal Article SR Electronic(1) A1 Gough, Keith H. A1 Shukla, Dharma D.YR 1980 T1 Further Studies on the Use of Protein A in Immune Electron Microscopy for Detecting Virus Particles JF Journal of General Virology, VO 51 IS 2 SP 415 OP 419 DO https://doi.org/10.1099/0022-1317-51-2-415 PB Microbiology Society, SN 1465-2099, AB SUMMARY The immune electron microscopic technique which involves pre-coating electron microscope grids with protein A before coating them with the specific antiserum, has been found suitable for detecting isometric insect and plant viruses. With the three virus-antibody combinations tested, the optimum antiserum dilution for protein A plus antiserum treatment was found to be 1:100 or less, whereas in the case of grids treated with antiserum alone it ranged from 1:1000 to 1:2000 although the titre of the antisera ranged from 1:512 to 1:4096. The increase in the number of particles on grids treated with protein A plus antiserum over those treated with antiserum alone, at each optimal antiserum dilution, was 25.7-fold (sugarcane mosaic virus), 2.1-fold (tobacco mosaic virus) and 1.6- and 2.4-fold (Erysimum latent virus — two different sap dilutions). Protein A plus antiserum-coated grids can be stored for up to 6 months at 4 °C, but not at room temperature or in a desiccator, and still retain about 25% of their activity, sufficient to detect any virus using the electron microscope. Antisera preserved in glycerol can be used successfully for detecting viruses by immune electron microscopy., UL https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-51-2-415