The Application of the Drop Volume Technique to Measurements of the Adsorption of Proteins at Interfaces.

A new procedure for the application of the drop volume technique to measurements of the rate of adsorption of proteins at interfaces has been developed. The mode of adsorption of the proteins lysozyme, β-lactoglobulin and bovine serum albumin (BSA) at the air-water interface has been measured with the drop volume method and has been compared to measurements with the Wilhelmy plate technique. Due to surface enlargement of the drop throughout the process of the surface tension decay, slower kinetics of the adsorption process is obtained by the drop volume method compared to the Wilhelmy plate technique, and the proteins investigated were differently sensitive to this surface expansion. The adsorption process of the proteins has been evaluated in terms of different rate-determining processes. Different intermediate states between the native and the denatured forms have been observed