Effect of pH, time, and dispersion on the appearance of neutral sialidase activity on treatment (40 minutes at 37°C) of erythrocyte white ghosts with the dispersing solution (5 mmol/L buffered PBS-0.15 mol/L NaCl, pH 8.0). The white ghost preparation used was the final pellet after erythrocyte lysis and washing, performed as described by Steck and Kant.35 The preparation of erythrocyte white ghosts was dispersed with 1, 5, 10, and 40 vol with the above dispersing solution. (□) neutral sialidase; (▪) acidic sialidase.