WILSON'S STAIN 



380 



XANTHOPROTEIC REACTION 



Wilson's Stain for Leishmania is compli- 

 cated. Details are provided by Craig, 

 p. 147 in whose opinion it gives no better 

 results than Wright or Leishman stains. 



Windaus, see Digitonine Reaction. 



Wintergreen Oil (methyl salicylate) is used 

 in the Spalteholz Method of clearing. 



Wislocki, see Placentas. 



Woad is a blue dye derived from the plant 

 Isatis tinctoria, now only of historic 

 interest, as it was replaced by indigo 

 after over a 1,000 years of supremacy in 

 Europe. When, nearly 2,000 years ago, 

 Julius Caesar's Roman legions crossed 

 the English Channel they encountered 

 a race of Celtic origin which they called 

 "Picts", or painted people, because 

 they had punctured their skins with 

 flints in many patterns and had rubbed 

 into them anil of the woad plant. The 

 account of this dye by Leggett is in- 

 teresting reading (Leggett, W. F., An- 

 cient and Medieval Dyes. Brooklyn: 

 Chemical Publishing Co., Inc., 1944, 

 95 pp.). Leggett quotes opinion of 

 Guest that the word "Britain" is the 

 Latinized form of Brythen, a Celtic 

 term, indicating "painted men". 



Woods Metal is now largely replaced by 

 celluloid in the making of corrosion prep- 

 arations. 



Wool Black B (CI, 315), an acid disazo dye 

 of light fastness 3 to 4 staining action 

 of which is briefly reported (Emig, 

 p. 38). 



Wool Green S (CI, 737) Lillie, R. D., J. 

 Tech. Methods, 1945, No. 25, 47 pp. has 

 reported this dye in a good combination 

 for connective tissue. Mordant sec- 

 tions 2 min. in sat. ale. picric acid. 

 Wash 3-5 times in running water and 

 stain 6 min. in Weigert's or other iron 

 hematoxylin. Wash in water and stain 

 4 min. in 1% Biebrich scarlet in 1% aq. 

 acetic acid. Wash in water and mor- 

 dant 4 min. in 10% dilution of U.S. P. 

 ferric chloride solution. Wash in water 

 and stain 4 min. in 1% aniline blue, 

 methyl blue, or wool green S in 1% aq. 

 acetic acid. Destain 2 min. in 1% aq. 

 acetic acid. Dehydrate and clear in 

 acetone, acetone and xylene and in 

 xylene. Mount in clarite in xylene or 

 in salicylic acid balsam. Connective 

 tissue and basement membranes, dark 

 blue or green; muscle and cytoplasm, 

 red. 



A substitute for Wright's stain is pro- 

 posed by Saye, E. B., Am. J. Clin. 

 Path., 1943, Tech. Suppl. 7, 12-13, made 

 up of Eosin Y and Thionin. It is 

 recommended for blood cells and mala- 

 rial parasites. 



Wool Orange 2G, see Orange G. 



Wool Red, see Amaranth. 



Wound Healing, method for study in vitro 



(Bentley, F. H., J. Anat., 1935-36, 70, 

 498-506). 



Wright's Blood Stain. This is a compound 

 stain of the Romanowsky type. The 

 Commission Certified (C.C.) product is 

 available. Dry the smear in air. Cover 

 the area between the wax lines with 

 stain measured by drops from a medicine 

 dropper. After 1 min. add same volume 

 aq. dest., shifting the slide a little from 

 side to side so that it mixes fairlj-^ well. 

 A green metallic looking scum forms on 

 the surface. Leave 2 or 3 min. Too long 

 staining produces a precipitate. It may 

 be necessary to use for dilution instead 

 of aq. dest. the McJunkin-Haden buffer. 

 Wash in tap water 30 sec. or more until 

 thin parts of smear become pink or yel- 

 low. Dry by blotting with smooth filter 

 paper and examine directly without 

 mounting in balsam and adding a cover 

 glass. Usually excellent results are ob- 

 tained. If however it is desired to em- 

 ploy buffered solutions especially for 

 sections consult Petrunkevitch, A., 

 Anat. Rec, 1937, 68, 267-280 and Lillie, 

 R. D., Stain Techn., 1941, 16, 1-6. The 

 other most used blood stain is that of 

 Giemsa with its several modifications. 

 Ehrlich's triacid stain is less used 

 nowadays . 



X Bodies, see Cytoplasmic Inclusions in 

 plants. 



Xanthene Dyes. As the name implies they 

 are derivatives of xanthene. They com- 

 prise many indicators and are classified 

 as acridines, fluoran derivatives, phe- 

 nolphthalein, pyronins, quinolines, rho- 

 damines, and sulfonphthaleins. 



Xanthene Dye, see Phosphine. 



Xanthine, see Purines. 



Xanthoproteic Reaction. Treat section 

 with cold fuming nitric acid. After a 

 few minutes the proteins become colored 

 yellow. Then rinse and expose to am- 

 monia vapor which changes the color to 

 orange. Not specific for proteins be- 

 cause there is also a nitration of aromatic 

 radicals of phenols, alkaloids, etc. The 

 color is often faint but fairly sharp 

 (Lison, p. 127). See also Bensleys 

 (p. 126). 



The reaction is described as follows 

 by Serra, J. A., Stain Techn., 1946, 21, 

 5-18: Fix tissue as given under Nin- 

 hydrin Reaction. "The pieces are 

 treated for some minutes with concen- 

 trated HNO3 until they become in- 

 tensely yellow. After a washing in 

 distilled water, immerse in a diluted 

 ammonia solution, or expose the pieces 

 to ammonia vapors. The color changes 

 to orange. The observation can be 

 made by mounting directly in pure 

 glycerin. 

 "The reaction is due to the presence 



