Abstract
It is a well know fact that the action of antiseptics upon bacteria is greatly diminished by the presence of proteins, blood serum, tissue juices and pus, but whether this is due to a chemical combination with the protein or to adsorption of the antiseptic on the surface of the protein, is not so certain.
Mathews, 1 Heidenhain, 2 and Chapman, Greenberg and Schmidt, 3 who advocated the theory of chemical combination, dealt with denatured lyophobic protein and not with protein in the natural lyophillic state; this has given rise to serious misconceptions. Ashley Cooper 4 has advanced some evidence that proteins adsorb phenols and do not enter into true chemical combination with them. The experiments of Grollmann 5 on the binding of phenol red indicate that the dyes are adsorbed, but the values (i. e., 1/N approximating 1) obtained lay too close to agreement with the mass law equation also to make fine distinctions possible. Rosenthal 6 also obtained an adsorption curve for the binding of rose bengal on a variety of proteins in acid solution.
If the reaction with protein is one of chemical combination, it should proceed in direct proportion to the reacting masses, while if it is an adsorption, it should follow the Freundlich adsorption isotherm (X/N = KCl/n) and give a logarithmic curve.
In order to study the reaction with proteins in their natural state, the protein (purified egg albumin) and dye were placed in a small wide-mouthed bottle containing, as a dialyzer, a segment of viscose sausage skin filled with water. The free crystalloid dye passes through the dialyzer until its concentration in the outside chamber is equal to that within, while any portion that is in colloidal form does not do so.
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