Development of a multichannel ultrasonic interferometer for the measurements under high pressures and its application to biomolecular studies

A description is given of a device that comprises four parallel fixed-path interferometric cells with a volume of 0.2 cc each. This device provides relative measurements of sound velocity with an error of about 10/sup -3/ to 10/sup -4/% in the pressure range of 1 to 2500 bar. The specific increments of the nonlinearity acoustic parameter B/A, for different biomolecular compounds (nucleotides, amino acids, and proteins), have been measured. The error of relative measurements of B/A is less than 0.5%. >