Improved cytochemical methods for demonstrating cell death using LR White as an embedding medium.

A series of techniques based on LR White resin are described, which permit the use of an anti-histone antibody for the in situ localization of DNA fragmentation characteristic of apoptosis at both the light and the electron microscope level. The methods, applied to an untreated squamous carcinoma of the pharynx, allow direct comparison of light microscopic localization of exposed nucleosomal histones using 3,3'-diaminobenzidine (DAB) and silver-enhanced techniques with a colloidal gold-based anti-histone technique at the electron microscope level. Parallel histochemical localization of acid phosphatase activity is also presented.