Modifications to the Gomori acid phosphatase technique for controlled-temperature frozen sections

The preservation of inert lysosomes in tissue sections depends on the use of the controlled-temperature freezing-sectioning technique. The Gomori procedure for acid phosphatase produces considerable disintegration of these unfixed sections. This disintegration is not due to incubation in the acid medium nor to the rinsing either in dilute acetic acid or in distilled water, but to the treatment with the solution of ammonium sulphide. It is suggested that for this solution there should be substituted a saturated aqueous solution of hydrogen sulphide gas, which does not cause such cellular deformation. Another improvement involves the deletion of the rinse in acetic acid, because this might render soluble some of the specific precipitate in sections showing minimal acid phosphatase activity.