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\-that such sites can be found on the surface membrane of normal cells after treatment with trypsin, and that the change in the surface structure from normal to transformed occurs in cells that are abortively transformed.Agglutination of cells by substances with different binding sites should be of value in elucidating the structural changes in the surface membrane that accompany the transformation of normal cells by carcinogenic agents. A substance from wheat germ that agglutinates transformed cells has previously been described.1' 2 Studies with this substance have indicated that this agglutinin is a glycoprotein,2 that the agglutination can be inhibited by competition with Nacetylglucosamine,2 3 and that after treatment with proteases, untransformed cells can be agglutinated and contain the same or similar receptor sites as transformed cells.4The present experiments were undertaken to find proteins with different binding sites that can be used for studies on the surface membrane of normal and transformed cells. It was found that when cells were dissociated with disodium versenate and not treated with trypsin, the crystalline Jack bean protein concanavalin A5 (ConA), which binds a-methyl-D-glucopyranoside6 7 and various other carbohydrates, agglutinated cells transformed by viral and nonviral carcinogens, but did not agglutinate normal cells and the untransformed cell line 3T3. The present communication reports the results of these experiments with 1418

Unsaturated free fatty acids such as oleic, arachidonic or linoleic at concentrations of 5-25 microgram/ml inactivate enveloped viruses such as herpes, influenza, Sendai, Sindbis within minutes of contact. At these concentrations the fatty acids are inocuous to animal host cells in vitro. Naked viruses, such as polio, SV40 or EMC are not affected by these acids. Saturated stearic acid does not inactivate any viruses at concentrations tested. Though the mode of action of unsaturated fatty acids is not understood, electronmicrographs of enveloped viruses treated by them indicate that the inactivation is associated with disintegration of the virus envelope.

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