The monitoring of lysosomal integrity by pH-stat and light scattering measurements.

Light scattering measurements were used to monitor the integrity of isolated rat kidney lysosomes during prolonged incubation at 37 degrees C or following the addition of lysolecithin. The fall in extinction at 520 nm (E520) was shown to correlate very well with the fall in the particulate enzyme activity and the corresponding rise in the soluble enzyme activity. Measurements were also made of the release of H+ from the lysosomes into the suspending medium following treatment with lysolecithin. A good relationship was obtained between acidification of the medium and changes in the light scattering (E520) of the lysosomal suspension. The value of these techniques in following rapid changes in the integrity of lysosomes is discussed.