Abstract
A simple and reliable method of separating and quantifying acid phosphatase activities in D. discoideum is described, and one of the electrophoretically distinguishable forms of the enzyme is shown to be specific for prestalk cells. Accumulation of this product commences some 2–3 h later in development than the prespore specific enzyme UDP-galactose polysaccharide transferase. This finding is discussed in terms of recent observations on the control of prestalk cell differentiation in this organism.