ANALYTICAL DIFFUSION OF INFLUENZA VIRUS AND MOUSE ENCEPHALOMYELITIS VIRUS.

Analytical diffusion has been applied to a study of influenza A virus in mouse lung, influenza A virus in the extra-embryonic fluids of the chick, and mouse encephalomyelitis virus in mouse brain. The results from influenza in mouse lung suggested that about 99 per cent of the infectivity was present in particles 200 mmicro in diameter, and 1 per cent in particles 6 mmicro in diameter. The results from influenza in extra-embryonic fluids indicated that the preparation was inhomogeneous and that the smallest virus units were about 6 mmicro in diameter. The results from mouse encephalomyelitis virus indicated that the preparation was also inhomogeneous, with 10 per cent of the infectivity in particles about 15 mmicro in diameter. It has been suggested that in virus preparations normal colloidal particles can act as carriers of much smaller virus units.