Search

In an already tumorigenic spontaneously transformed mouse cell, after further transformation by SV40, the virus-specific antigenic function becomes dominant. By transplantation into syngeneic mice SV40 antigen negative revertant tumour cells can be selected out.

Following morphological transformation of mouse cell lines in culture by a murine sarcoma virus, a decrease occurs in a single glycolipid glycosyltransferase. This same enzyme change has been observed previously in DNA-virus-transformed cells, but is not seen after infection with a non-transforming murine leukaemia virus.

SYNTHETIC polysaccharides can be prepared from simple carbohydrates differing not only in molecular weight but also in degree of branching1. From such polyglucoses, various charged derivatives can be prepared, for example, a series of sulphuric acid esters with different degrees of sulphonation. The synthetic polysaccharide derivatives provide a system of ‘macro-anions’ the composition, macromolecular and polyelectrolyte properties of which can be altered systematically. Interaction of other kinds of macro-anions with certain proteins and polypeptides had been found to: alter solubility and thus make possible development of new fractionation and preparative methods2; inhibit, often reversibly, a large number of enzymes3; and show some similarity to antigen–antibody precipitation.

Reduction of Toxicity of Cationic Macromolecules by Complexing with Anionic Derivatives of Synthetic Polyglucoses

WITH so much research being carried out on bacterio-phage, improvements to simplify and save time in the routine techniques of assay and preparation would be of great value. Having spent considerable time on preparation of ‘bottom’ agar plates for the agar layer assay by the plaque count method1,2 and for high-titre bacterio-phage stock preparation on a large number of plates by the confluent lysis method3, we investigated the possibility of saving time by using plates without ‘bottom’ agar for assay and stock preparation.