title: A note on the use of picric acid-paraformaldehyde-glutaraldehyde fixative for correlated light and electron microscopic immunocytochemistry.
abstract: The buffered picric acid paraformaldehyde fixative originally recommended for electronmicroscopy and which has since been used occasionally for light-microscopic immunocytochemistry, has been supplemented with glutaraldehyde and used as primary fixative for the perfusion of rat brains. In the basal ganglia and preoptic area, substance P, somatostatin and leu-enkephalin immunoreactive material was localized with the unlabelled antibody enzyme method in thick sections cut from freeze-thaw treated blocks. Good penetration of the antibodies without the use of detergents and the light background of the osmium-treated sections allowed the selection for electron-microscopy of immunoreactive structures as small as individual boutons that had been identified at the light-microscopic level. It is suggested that the procedure may be useful for electron-microscopic sampling of immunoreactive structures occurring infrequently over a large area or for the electron-microscopic study of light-microscopically classified neurons.
mesh_terms: D000818:Animals; D001369:Axons / Q000648:ultrastructure; D001921:Brain / Q000033:anatomy & histology*; D004743:Enkephalin, Leucine / Q000378:metabolism; D005404:Fixatives; D005557:Formaldehyde; D005976:Glutaral; D006652:Histological Techniques; D007124:Immunoenzyme Techniques; D008297:Male; D008854:Microscopy, Electron; D009115:Muridae; D009474:Neurons / Q000648:ultrastructure; D018377:Neurotransmitter Agents / Q000378:metabolism*; D010851:Picrates; D011108:Polymers; D013004:Somatostatin / Q000378:metabolism; D013373:Substance P / Q000378:metabolism; D013569:Synapses / Q000648:ultrastructure
chemical_list: D005404:Fixatives; D018377:Neurotransmitter Agents; D010851:Picrates; D011108:Polymers; D005557:Formaldehyde; D013373:Substance P; D013004:Somatostatin; D004743:Enkephalin, Leucine; C005858:picric acid; D005976:Glutaral; C003043:paraform