Immunological experiments with highly concentrated suspensions of the Rous I tumour‐producing agent

Virus or Avian Myeloblastic Leukosis

“…It should be said, at once, however, that little has been done to substantiate this view. Host tissue has been found in concentrâtes of chicken tumor virus (Amies, 1937;Amies and Carr, 1939) and of several forms of leukosis Furth, 1940, 1941), but no évidence has been presented to characterize the concentra ted materials. Knight (1946) has reported the présence of normal chick antigen or mouse tissue antigen, depending on the source of the agent, in the influenza virus.…”

The Association of Haemin with the Fowl Cancer Viruses

“…The details of the methods of concentrating varied somewhat (see Amies & Carr, 1939;Carr & Harris, 1951). The 'normal particles ' or macromolecular preparations which result by applying similar methods to normal fowl tissues or to two chemically induced and nonfilterable fowl sarcomas (obtained by courtesy of J. McIntosh & F. R. Selbie, and P. R. Peacock) appeared to be colourless.…”

“…It was noticed that preparations of fowl sarcoma viruses made by fractional centrifugation of tumour extracts and enzyme digestion (Amies & Carr, 1939;Carr & Harris, 1951) gave slightly cream-coloured suspensions and yellowbrown pellets when centrifuged, in contrast to most other viruses, e.g. vaccinia, concentrates of which are a dead chalky white.…”

Pigment spread in mammalian skin: serial propagation and immunity reactions

“…That the infective agent is highly complex cannot be doubted, since it carries the antigenic specificity of the individual and is destroyed by active immunisation with grafts of white skin as well as black. Its complexity is perhaps analogous to that of the Rous fowl sarcoma virus, which is known to contain an immunologically chicken-specific component (Amies and Carr, 1939) ; this type of association between viruses and the ingredients of normal cells is by no means rare (cf. the reviews of Pine, 1946, andKidd, 1946).…”