Tobacco mosaic virus: purifying and sorting associated particles accordig to length.

End-to-end aggregation of tobacco mosaic virus and associated particles during extraction and purification may be prevented by transfer of the virus to 0.001M buffer solution of ethylenediaminetetraacetic acid, pH 7.5, as rapidly as practicable. Colored components were removed with charcoal and diatomaceous earth, and salts by rapid passage through a column of granulated 8 percent agar gel. The virus particles were sorted according to length by passage through a 1 percent granulated agar-gel column to isolate the 300- and 200-mmicro fractions and through a 5 percent agar gel to isolate the shorter particles.