The study of autolysis by physico-chemical methods

Further studies of autolytic changes in animal tissues by means of the depression of the freezing point and rise in conductivity show the great value of these methods of estimating the rate and progress of autolysis. The results obtained in this way give a much more accurate and valuable indication of autolytic changes in any given tissue than the commonly used determination of the percentage of nitrogen in coagulable form. Autolysis comprises the disintegration of the cell components and involves a great many substances, some of which are coagulable proteins and many of which are not. If we determine the proportion of nitrogen that is made non-coagulable by heat, we get a figure which is the same whether the coagulable nitrogen that has been made incoagulable is in the form of proteoses and peptones, or has been carried to the ultimate amino-acids or even further. The several steps that take place in the autolysis of nucleins also have no effect on this figure after the first splitting out and rendering soluble of the nucleic acid complex. Only the autolytic changes which affect coagulable or insoluble nitrogenous cellular constituents are shown, and the changes in such substances as collagen or the other non-coagulable nitrogenous tissue elements are not brought out. In other words, the ratio of coagulable and non-coagulable nitrogen in autolyzing tissues shows only one of the many changes that are being accomplished by the autolytic processes.