RESUMO
Highly pure lysosomes were isolated from buffalo (Bubalus bubalis) kidney cortex by a procedure involving differential and isopycnic Percoll density gradient centrifugations. Arylsulphatase, N-acetyl-ß-glucosamindase and cathepsin D in the lysosomal preparation were 26-45-fold enriched over the homogenate. The purified lysosomes contained less than 0·06% of mitochondrial, microsomal and peroxisomal marker enzymes. In the electron micrographs the particles appeared as large dense granules of size 0·3–1·9 μm with no apparent structural features belonging to mitochondria or microsomes. The isolation procedure was also found to be suitable to obtain highly pure lysosome particles from renal cortex of other sources such as rat, lamb and beef. No ultracentrifugation steps were involved in the procedure.