Isolation of intact plankton from drowning lung tissue by centrifugation ina colloidal silica gradient

Several species of intact phyto- and zooplankton from the homogenate of rat "drowning lung" were separated by centrifugation in a colloidal silica gradient. The plankton, except diatoms, were isolated from a small amount of human "drowning lung" by this procedure. This new method was found to be more useful in detecting plankton in tissues than chemical digestion with strong acid.