MEASUREMENT OF CELL LYSIS BY LIGHT SCATTERING

Abstract— A method is presented which is capable of continuously monitoring the degree of hemolysis in erythrocyte suspensions too dilute to be monitored by conventional light transmission techniques. Scattered light is used to non-destructively assess hemolysis in sparse monolayers which are particularly well suited to many photohemolytic studies. The small angle scattering (<10°), measured here, shows a transient decline as cells settle in a culture dish and then is constant if no lysis occurs. Lysis is indicated by a decrease in scattered light to < 20% of initial intensity when lysis is complete. The light used to monitor lysis is restricted to wavelengths longer than 700 nm which is outside the absorption band of many. photosensitizers of current interest, and is a wavelength range at which light scattering is relatively independent of changes in cell volume. In photohemolytic studies with phloxine B lysis values from light scattering are shown to correlate well with lysis values from hemoglobin release. An apparatus is described which is capable of periodically measuring lysis in eight suspensions without intervention by the experimenter.