Ultrastructural demonstration of acetylcholinesterase activity of motor endplates via osmiophilic diazothioethers

Electron Microscopic Demonstration of Cholinesterase in the Human Intercostal Muscle by an Indoxyl Acetate Esterase Method

“…Bergman et al (4) stated that their results seemed worth publishing as an interim stage of study though the droplet stain was not an ideal endproduct. Actually, they could not observed the precise location of esterase in spite of a remarkable electron density.…”

“…Cholinesterases have been demonstrated with several electron microscopic methods involving both metal capturing thiolacetic acid and thiocholine methods and azo dye methods (1)(2)(3)(4)(5)(6)(7)(8)(11)(12)(13). Although the former methods have their own hazards for the staining artifacts, for example a possible nonenzymatic reaction of lead salt, a question on the conversion technique to metal sulfide and large crystalline structure of the reaction product, it has been shown recently that aurous gold capturing method demonstrates excellently the localization of acetylcholinesterase and nonspecific cholinesterase (7).…”

“…The most recent work in the latter reveals small droplet endproducts at the sites of the enzyme activity of which appearance proves to be a disadvantage of the azo dye method (4). In this study, therefore, a new azo dye method was employed in order to confirm the exact localization of cholinesterase.…”

Histochemical Demonstration of Acid and Alkaline Phosphatase Using 2-Naphthylthiolphosphate as Substrate and Osmiophilic Derivatives as End Products

“…A new histochemical principle was introduced (14, 27) which provides a method for visualizing a variety of enzymatic reactions (4,29,30,31,33) and functional groups (32) in tissue. By the use of reagents which yield osmiophilic reaction products, osmium blacks are obtained on osmication and some of these coordination polymers (15) are ideal end products for electron microscopy.…”

Electron Microscope Radioautography as a Quantitative Tool in Enzyme Cytochemistry

“…One hopes that finer localization will come from EM histochemistry which potentially has a much higher resolution than does EM radioautography. Unfortunately, however, problems of diffusion of reaction product have prevented, in several studies with EM histochemistry, the utilization of this higher resolution and the reaching of an agreement on whether the enzymes are located only on the membranes (Davis and Koelle, 1967 ;Bergman et al ., 1967) or in the clefts as well (Barrnett, 1962 ;Zacks and Bloomberg, 1961 ;Lehrer and Ornstein, 1959 ;Csillik, 1965) . Recent studies have even suggested a postjunctional cytoplasmic localization for AChE (Teravainen, 1967) .…”