Purification and concentration of the virus of foot-and-mouth disease by combined centrifugation and ultrafiltration methods

Abstract

1. It is possible to concentrate the virus of foot-and-mouth disease on filter candles coated with acetic acid collodion. The degree of concentration of the virus effected was to the limit of expectancy, i.e. the increase in titre after concentration corresponded to the reduction of the volume of the liquid.2. By a combination of the two methods of purification of the virus, viz. washing once in the closed agar-lined cylinder of the Sharpies-Super Centrifuge and repeatedly on a graded collodion membrane of A.P.D. 25 mμ, very potent purified concentrates of virus can be rapidly obtained, especially if the final concentration is made on filter candles, coated with acetic acid collodion. In this way a concentrate of virus with a titre of 10−8 and a negative sulphosalicylic acid test for protein has been prepared in one day from virulent vesicle lymph (diluted 1 : 2) having a titre of 10−6.3. The possibilities of the different methods of purification and concentration of the virus are discussed and a scheme suggested for their application.