Purification of Dictyostelium discoideum spores by centrifugation in percoll density gradients with retention of morphological and biochemical integrity

Rapid and reliable methods have been developed for the preparation and purification of dormant spores of the cellular slime mold, Dictyostelium discoideum, using Percoll density gradient centrifugation. Percoll gradients were generated in situ (20,000g; 30 min) with subsequent banding of nondamaged dormant spores at an isopycnic density equal to about 1.12 g/cm³. Examination of the prepared spores by phase-contrast microscopy indicated the absence of stalk cells and other nonspore material and the retention by the spores of their morphological integrity. Biochemical integrity was also retained by the isolated spores as evidenced by their efficiency of germination and the level of endogenous trehalase activity present in crude cell-free spore extracts.