Modification of Lowry's method for collagen concentration measurement.

A procedure for the determination of collagen concentration is described. It is simple and sensitive and is based on a modification of Lowry's method. The modification includes an initial heating of collagen samples in alkaline solution and changes in the concentrations of reagents used. It may be used for different collagen types, i.e. I, II, V and XI, from various sources as well as for gelatine. The influence of different buffers, salts, detergents, etc. on the precision of the method was studied. The precision of the measurements was not influenced by pH, the turbidity of the sample and the presence of certain salts, osmolytes and preservatives, routinely used in biochemical, microbiological and immunological experimental protocols. The modification is suitable for routine determinations of collagen concentration in a wide variety of samples.