%0 Journal Article %A Bradish, C. J. %A Henderson, W. M. %A Kirkham, J. B. %T Concentration and Electron Microscopy of the Characteristic Particle of Foot-and-Mouth Disease %D 1960 %J Microbiology, %V 22 %N 2 %P 379-391 %@ 1465-2080 %R https://doi.org/10.1099/00221287-22-2-379 %I Microbiology Society, %X SUMMARY: The infective component of the virus system of foot-and-mouth disease was concentrated and purified by ultracentrifugation and solvent extraction. Infective materials derived from ox, guinea-pig, mouse, chicken, goose and tissue culture were employed. The infective concentrates (D-fractions) and the separated smaller complement-fixing components (U-fractions) were characterized by infectivity, complement-fixing activity and nitrogen content. The D-fractions, of activity up to 1014·5 ID50/g. N, represented less than 0·1% of the initial protein content. Electron micrographs of the D-fractions showed clusters and hexagonal arrays of 25 to 27 mμ ‘spherical’ particles of granular structure. These defined fractions of the virus system were used in a number of subsequent investigations. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-22-2-379