Abstract:
(1) Details of the technique employed for the preparation of gradocol membranes are given together with the technique employed in the filtration of neurotropic horsesickness virus.
(2) From data collected from the filtration of 6 strains of virus it is found that the limiting membrane is one with a porosity of 100 mµ. Hence the diameter of the virus particles is from 40-60 mµ with a mean of 50 mµ.
(3) Details of the technique used for determinations by the
inverted capillary method of centrifugation are given.
(4) The method used for determining the density of the virus
particles is given. By this method a density of 1.25 gm. per c.c. was calculated.
(5) By the centrifugation method a mean value of 45.4 mµ for the particle diameter was calculated.
(6) The particle diameter determined by both methods agree
closely.
(7) There was no significant difference in the size of the virus
particles of 6 strains of different antigenic structure.
