Ultrasonically activated gas-filled micropores release hemoglobin and antigens from human erythrocytes in vitro.

Antigen release from human type B red blood cells was investigated by sensitive capillary-tube assay techniques after subjecting 3% suspensions to a controlled form of ultrasonic cavitation. Cells were kept suspended during the 1,000-sec exposures by an orbital motion of the sample chamber. Several spatial peak intensities of continuous 1.7 MHz ultrasound were applied to the samples which included gas-filled 4-microns diameter micropores in hydrophobic membranes. Free hemoglobin, indicating hemolysis, and free antigenic material, indicating solubilization of antigens, were found in the supernates of suspensions exposed to 90 mW/cm2 or 180 mW/cm2, respectively, or greater intensities. None of the free antigenic material could be attributed to antigen loss by surviving cells. For these conditions, the antigen release effect of ultrasound appears to be a byproduct of cavitation-induced cell lysis.