Ultrasonic absorption of bovine serum albumin solutions in the frequency range 200 kHz-1 MHz.

The ultrasonic absorption of solutions of two electrolytes, magnesium and manganous sulfates, and also of the globular protein bovine serum albumin, has been measured using small volume spherical resonators at frequencies in the range 200 kHz-1.2 MHz. The principles of the technique are discussed and absorption values obtained for the electrolyte solutions at 20 degrees C are compared with existing values using other methods. For BSA, measurements were made at 8 degrees C over a range of pH values. Under both acid and alkaline conditions, excess losses at megahertz frequencies were found to persist down to at least 200 kHz. A new loss peak at approximately 400 kHz has been found at pH 3.2.