Prevention of negative chemography in phenylenediamine stained autoradiographs of plastic semithin sections.
Negative chemography is the loss of latent image during autoradiographic exposure, due to reactive groups in the specimen. Tissue fixed with glutaraldehyde and osmium tetroxide, block stained with p-phenylenediamine and embedded in Epon for light microscope sections causes intense negative chemography when autoradiographed by dipping in Ilford K2 emulsion: this cannot be completely prevented by separating section from emulsion by means of a layer of evaporated carbon. Chemical treatment of the sections before autoradiography may reduce the chemography. Treatment with 1% hydrogen peroxide for 15 min reduced it to such an extent that subsequent coating with 5 nm carbon abolished it. Material block stained in this way gave excellent contrast, both for light and electron microscopy.
D000818:Animals; D001345:Autoradiography; D001980:Bronchi / Q000033:anatomy & histology; D002244:Carbon; D055598:Chemical Phenomena; D002621:Chemistry; D005188:False Negative Reactions; D005404:Fixatives; D006801:Humans; D006861:Hydrogen Peroxide; D007420:Intestine, Large / Q000033:anatomy & histology; D007421:Intestine, Small / Q000033:anatomy & histology; D008168:Lung / Q000033:anatomy & histology; D008297:Male; D051379:Mice; D009993:Osmium Tetroxide; D010655:Phenylenediamines; D013194:Staining and Labeling
D005404:Fixatives; D010655:Phenylenediamines; D002244:Carbon; D006861:Hydrogen Peroxide; D009993:Osmium Tetroxide; C029728:4-phenylenediamine