NUCLEOTIDES 



242 



ONCOCYTES 



review of the literature (Mendes Fer- 

 reira, H. E., J. Lab. & Clin. Med., 1940- 

 41, 26, 1612-1628). 



Nucleotides, see Diphosphopyridine Nucleo- 

 tide and Pentose Nucleotides. 



Nutriles, growth promoting (Williams, R. 

 J., Biol. Rev., 1941, 16, 49-80). 



Oil Blue NA (Calco) a stain which colors 

 rubber bright blue in various plant 

 species (Whittenberger, R. T., Stain 

 Techn., 1944, 19, 93-102). This dye is 

 also a good stain for fat in animal cells 

 (Lillie, R. D., Stain Techn., 1945, 20, 

 7-9). 



Oil Immersion, see Immersion Oils. 



Oil Red IV, see Sudan IV. 



Oil Red AS, O, B or 3B, see Sudan III. 



Oil Red O (CI, 73).— fast oil orange II, fat 

 ponceau, oil scarlet, orange RR, red B, 

 Sudan II — an acid mono-azo dye sug- 

 gested as fat stain by French, R. W., 

 Stain Techn., 1926, 1, 79. Proescher's 

 (F., Stain Techn., 1927, 2, 60-61) oil red 

 pyridine stain for fat is to immerse 

 frozen sections of formalin, Muller- 

 formalin (see Muller's fluid) and 5 cc. 

 10% formalin in 100 cc. sat. aq. picric 

 acid fixed tissues in 50% aq. pyridine, 

 3-5 min. Stain 3-5 min in 3-5 gms. oil 

 red O dissolved in 100 cc. 70% aq. 

 pyridine C.P. Differentiate in 50% 

 pyridine several minutes and counter- 

 stain for 2-3 min. in Delafield's Hema- 

 toxylin. Mount in levulose syrup. For 

 central nervous system differentiate 

 30 min. in pyridine and use 16 cc. Dela- 

 field's + 2 cc. glacial acetic acid. Ac- 

 cording to Proescher, oil red O stains 

 fats and lipids more intensely and 

 quickly than Sudan III or IV. 



Oil Scarlet, see Oil Red O. 



Oil Soluble Dyes. List with physical prop- 

 erties of each and use as fat stains. 

 Very comprehensive (Lillie, R. D., J. 

 Tech. Methods, 1944, 24, 37-45). 



Oil Vermillion, see Sudan R. 



Okajima's "omnichrom" stain (Ito, T., 

 Folia Anat. Jap., 1937, 15, 357-359). 



O'Leary's Brazilin Method — Revised by 

 James L. O'Leary, Dept. of Neuro- 

 psychiatry, Washington University, St. 

 Louis, May 8, 1950 — For myelin sheaths. 

 Run paraffin, or celloidin sections of 

 properly fixed and mordanted (Muller's 

 Fluid) tissue to water. After rinsing 

 transfer to 3% aq. potassium bichro- 

 mate or in Muller's fluid, 12-24 hrs. 

 Stain in: 10% Grubler's Brazilin in 

 abs. ale. (1-6 months old), 10 cc; aq. 

 dest., 100 cc; acetic acid, glacial, 5 

 drops. Wash in aq. dest. Differ- 

 entiate in 0.25% aq. potassium per- 

 manganate 1-5 min. Remove potassium 

 permanganate with Weil's solution 

 (oxalic acid, 2.5 gm.; sodium bisulphite, 

 2.5 gm.; aq. dest. 1,000 cc.) Sections 



should show gray matter light pink, 

 white matter brilliant red. Cell bodies 

 stain in addition to mj^elinated fibers. 

 If differentiation not complete after 

 first immersion in potassium perman- 

 ganate followed by oxalic acid-bisul- 

 phite mixture, repeat the procedure. 

 Wash, dehydrate and mount. See 

 Golgi-Cox Method and Golgi Method, 

 Quick. 



Oligodendroglia. Method for impregna- 

 tion with silver in pyroxylin (celloidin) 

 sections (Weil, H. and Davenport, H. 

 A., Trans. Chicago Path. Soc, 1933, 14, 

 95-96). This resembles their Microglia 

 method. Wash sections in aq. dest. 

 and transfer to aq. dest. containing 1 

 drop cone, ammonia per 10 cc. Treat 

 for 15-20 sec. with silver solution made 

 up as for microglia except that 15% 

 aq. silver nitrate is used and the end 

 point of the titration is reached when 

 about 12 cc. of it have been added to the 

 2 cc. cone, ammonia. Transfer to 10% 

 formalin and allow section to drop to 

 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). 



Oliver, see Kidney. 



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

 Transplants of spleen into (Holyoke,E. 

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



Oncocytes (G. onkos, tumor, swelling -f- 

 kytos, cell). These cells are recogniz- 

 able in ordinary hematoxylin and eosin 

 preparations by their (1) large size, (2) 

 usually single centrally placed picnotic 

 nuclei and (3) the large volume of finely 

 granular eosin staining cytoplasm in 

 proportion to nuclear volume. They 

 are most frequently encountered in the 

 parotid and submaxillary glands but 

 they have been reported in many other 

 epithelia including those of the thyroid, 

 parathyroid, pituitary, pancreas, liver, 

 stomach, Fallopian tube, uvula, nose, 

 pharynx, trachea and esophagus. 

 Nohteri, H. (Acta Path, et Micr. Scand., 

 1946, 23, 473-483) found them only in 

 individuals over 52 years of age. Ham- 

 perl, H. (Virchow's Arch., 1937, 298, 

 327-375) reported that they are very 

 rarely seen under 50. An excellent 

 cytological account of oncocytes in the 

 salivary glands of a large series of 

 animals of known age is provided by 



