title: Examination of the rat eye at the early stage of development with osmium tetroxide staining.
abstract: This communication describes the benefit of osmium tetroxide (OsO4) staining on the examination of the eye during the early stage of organogenesis of rat embryos. The embryos were obtained by laparotomy on embryonic day 12 (ED 12) and were stained with OsO4 for examination of the ocular tissues with a binocular stereo-microscope, light microscope and scanning electron microscope. At the binocular stereo-microscopic level, the invaginated lens placode, lens pit and optic cup were clearly distinguished. The osmium-stained lens placode and the optic cup were light brown and dark brown in color, respectively. Light microscopic examination revealed that OsO4 postfixation could provide superior paraffin-embedded embryonic sections. Scanning electron microscopic examination revealed the lens pit as a round opening between the lateral nasal prominence and maxillary prominence. Thus, a rapid technique by which the ocular tissues of rat embryos can be examined under a binocular stereo-microscope was developed. This OsO4 staining method will provide a useful tool for research on organogenesis and ocular development.
authors.affiliation: Department of Safety Assessment, Development Research Laboratories, Banyu Pharmaceutical Company Ltd., 810 Nishijo, Menuma, Osato, Saitama 360-0214, Japan. inagkist@banyu.co.jp
authors.forename: Satoru
authors.initials: S
authors.lastname: Inagaki
authors.forename: Tadao
authors.initials: T
authors.lastname: Kotani
mesh_terms: D000818:Animals; D004396:Coloring Agents; D003941:Diagnostic Techniques, Ophthalmological / Q000662:veterinary*; D005123:Eye / Q000196:embryology* / Q000648:ultrastructure; D005260:Female; D008297:Male; D009993:Osmium Tetroxide; D011247:Pregnancy; D051381:Rats; D011919:Rats, Inbred Strains / Q000196:embryology*; D013048:Specimen Handling / Q000662:veterinary
chemical_list: D004396:Coloring Agents; D009993:Osmium Tetroxide