Searching the agents that are capable of effectively suppressing protein aggregation and elaboration of the corresponding test systems are among the most important problems of modern biochemistry and analytical biochemistry . To characterize the anti-aggregation activity of different agents including chaperones of protein nature and low-molecular-weight chemical chaperones, test systems where the initial state of a target protein is the native protein that undergoes unfolding and subsequent aggregation under the action of different factors are mostly used. Unfolding of the target protein can be caused by heating at elevated temperatures. For several proteins the unfolding process can be initiated by the cleavage of S-S bonds in the protein molecule. Dithiothreitol (DTT)-induced aggregation was demonstrated, for example, for a-lactalbumin, insulin, lysozyme and bovine serum albumin (BSA).