The effect of formaldehyde and mercuric chloride on tobacco mosaic virus

Abstract

Inactivation of infectivity of tobacco mosaic virus proceeds at all pH values between 3 and 7.5, the rate of inactivation being minimal around pH 3.5. The degree of inactivation is not necessarily correlated with changes in groups giving Folin''s pH 8 color test or the Van Slyke test for amino N. The progress of inactivation could be stopped at any stage by dilution or by dialysis, but it could not be reversed by these treatments. HgCl2 in sufficient concs. acts as an inhibitor of infectivity of the virus. At pH values > 6 it causes loss of infectivity and serol. activity. Dilution, acidification or addition of certain salts prevents inactivation or interrupts its progress at any stage, but there is no evidence that any of these treatments can reverse it.