The pH of Serum Inactivated by Heat

Abstract

WE have shown, in recent years, that the inactivation of serum, or destruction of alexin by heat, is accompanied by a number of physical or physico-chemical phenomena which characterise the critical temperature of 55°–57° C. They are: increase in viscosity (after an absolute minimum around 56°¹), increase in rotatory power², increase in absorbed light³, increase in scattered light³, increase in the factor of depolarisation⁴, increase in electric resistivity⁵, sharp change in the rate of sedimentation of globulins after dilution with water⁶, decrease in the amount of ether fixed by shaking⁷, change in the interfacial tension against oils⁸. A new phenomenon is to be added to the list, namely, an increase in the hydrogen ion concentration, expressed by a drop in the pH.