OLIGODENDROGLIA 



179 



OSAGE ORANGE PIGMENTS 



bottom without moving dish. After 

 the pyroxylin has become deeply stained 

 and the tissue begins to take a brown 

 color, move it with glass rods until it is 

 stained coffee-brown. Use fresh forma- 

 lin for each section. Pass section 

 through 3 changes aq. dest. Dehydrate 

 in alcohol, clear in xylol and mount in 

 balsam. 



Olive Oil, reactions in tissue to fat stains 

 after various fixations (Black, C. E., 

 J. Lab. & Clin. Med., 1937-38, 23, 

 1027-1036). 



Omentum, spreads of (McClung, p. 336). 

 Transplants of spleen into (Holyoke.E. 

 H., Am. J. Anat., 1940, 66, 87-132. 



Opsonocytophagic Index, method for rapid 

 staining of blood smears in (Bondi, A. 

 Jr., J. Lab. & Clin. Med., 1941, 26, 1811). 

 Derivation of index number in (Foshay, 

 L., LeBlanc, T. J., J. Lab. & Clin. Med., 

 1936-37,22, 1297-1300). 



Opal Blue (CI, 689)— Aniline Blue, alcohol 

 soluble. Bleu Lumiere, Gentiana Blue 

 6B, Spirit Blue — a basic dye of light 

 fastness 3, to be employed in contrast 

 staining with Biebrich Scarlet, Crocein 

 Scarlet and other dyes (Emig, p. 50). 



Optic Lens, methods of microincineration 

 and histospectrography as applied to 

 cataracts of various sorts and normal 

 lenses with special attention to copper, 

 zinc and iron (Busnel, R. G., Fillet, P. 

 and Tille, H., Bull. d'Hist. AppL, 1938, 

 15, 99-109). 



Oral Mucosa. Smear method for study of 

 keratinization (Weinmann, J., J. Dent. 

 Res., 1940, 19, 57-71). With end of 

 agate spatula gently scrape area about 

 1.5 sq. cm. Smear on slide, dry in air 

 and stain for 30 sec. in : sat. ale. gentian 

 violet (or better crystal violet) 10 cc. + 

 6% aq. phenol, 90 cc. Lugol's Iodine, 

 30 sec. Wash in water until no more 

 color is extracted. Counterstain for 

 2 min. in sat. safranin O in 95% alcohol, 

 10 cc. -f- aq. dest., 100 cc. Wash in 

 water 2-3 sec, dry and mount in balsam. 



Orange I (CI, 150). Synonyms: naphthol 

 orange, tropaeolin G or 000 No. 1. An 

 acid mono-azo dye used as an Indicator. 



Orange II (CI, 151). Synonyms : acid 

 orange II, Y or A, gold orange, mandarin 

 G, orange A, P, or R, orange extra, 

 tropaeolin 000 No. 2. An acid mono- 

 azo dye. Ebbinghaus, H., Centralbl. 

 f. allg. Path. u. Path. Anat., 1902, 13, 

 422-425 employed gold orange with 

 hematoxylin as a special stain for keratin. 



Orange III, see Methyl Orange. 



Orange A, P, or R, see Orange II. 



Orange Extra, see Orange II. 



Orange G (CI, 27). Synonym; wool orange 

 2G. Of slightly different grade ac- 

 cording to Conn (p. 47) are orange GG 

 and GMP. An acid mono-azo dye 

 widely used. 



Orange MNO or MN, see Metanil Yellow. 



Orange R (CI, 161), an acid monoazo dye of 

 light fastness 3-4 action of which on 

 plant and animal tissue is described 

 (Emig, p. 33). 



Orange RR, see Oil Red O. 



Orcein (CI, 1242) is a natural dye produced 

 from lecanora parella (a lichen) and 

 should not be confused with orcin pro- 

 duced from the same plant. It is now 

 prepared synthetically. Its precise for- 

 mula remains to be determined but it 

 is a most valuable stain for Elastic 

 Fibers. Mollier,G.,Zeit. f. wis. mikr., 

 1938, 55, 472-473 employed it with iron 

 hematoxylin, naphthol green B and 

 azocarmine G. Acetic-orcein is advo- 

 cated as a new stain-fixative for chromo- 

 somes (LaCour, L., Stain Techn., 1941 

 16, 169-174). An acid orcein Giemsa 

 is described for use in dermatology by 

 Pinkus, H., Arch. Dermat. and Syph., 

 1944, 49, 35.5-356. 



Orceille, a purple dye, derived from Lichens 

 growing on the rocks of tho Near East 

 and Mediterranean areas, achieved 

 great favor among the ancients being 

 said by Theophrastus and Dioscorides 

 to even excel Tyrian Purple. A Floren- 

 tine dye trader, Federigo, promoted 

 this dye, built up a thriving business and 

 calling himself Orcelli, founded a large, 

 distinguished and prolific family (Leg- 

 gett, W. F., Ancient and Medieval 

 Dyes. Brooklvn: Chemical Publishing 

 Co., Inc., 1944;' 95 pp.). 



Origanum Oil. With it tissues can be 

 cleared from 95% alcohol, but care must 

 be taken to obtain a pure product. 

 The kind required consists of carvacrol 

 and cymene terpenes. Ordinary 

 origanum oil is oil of thyme. 



Orseillin BB (CI, 284). A little used acid 

 dis-azo dye. See Cohen, I., and Doak, 

 K. D., Stain Techn., 1935, 10, 25-32. 

 For staining fungi (Alcorn, G. D. and 

 Yeager, C. C, Stain Techn., 1937, 12, 

 157-158). 



Orthochromatic Erythroblasts, see Ery- 

 throcytes, developmental series. 



Orth's Fluid. Potassium bichromate, 2.5 

 gm.; aq. dest., 100 cc, formalin, 10 cc. 

 The 1 gm. sodium sulphate originally 

 advised by Orth is omitted as useless. 

 Since the fluid docs not keep it should 

 be made up immediatelj'^ before use. 

 Regaud's fluid, the best fixative for 

 mitochondria, is the same except that 

 the amount of formalin is increased 

 See Lithium Carmine (Orth). 



Osage Orange Pigments n.s brilliant mordant 

 dyes for wool and silk. Wolfsom, 

 M. L., Harris, W. D., Johnson, G. F., 

 Mahan, J. E., Moffett, S. M. and Wildi, 

 B., J. Am. Chem. Soc, 1040, 68. 406- 

 418.yiShould be tried on animal tissues. 



