DIANIL BLUE 2R 



80 



DIPHTHERIA BACILLI 



lutea and mammary glands but these 

 authors do not employ the name : dianil 

 blue. 



'Manil Red 4B, see Benzopurpurin 4B. 

 iianthine B, see Erythrosin, bluish. 



:Jiaphane for mounting Giemsa preparations 

 (Coulston, F., J. Lab. & Clin. Med., 

 1940, 26, 869-873). 



Diaphanol is according to Lee (p. 598) the 

 trade name for a mixture, formerly 

 obtainable from Leitz, produced by 

 passing chlorine dioxide vapor into ice 

 cold 70% acetic acid. It should be 

 fresh. He advises against attempts to 

 make it and outlines its use in the soft- 

 ening of Chitin. Rinse well fixed tissues 

 in 63% alcohol and transfer them to 

 diaphanol until they are softened and 

 bleached. If the diaphanol becomes 

 discolored, repeat. Transfer to 63% 

 alcohol, dehj^drate, clear in tetralin 

 (if not available, benzol) and imbed in 

 paraffin. See use of diaphanol in 

 demonstrating Melanins. 



Diazo Reaction. Serra, J. A., Stain Techn., 

 1946, 21, 5-18 gives the technique as 

 follows: Prepare tissue as described 

 under Ninhydrin Reaction. "Treat the 

 pieces for 2-3 minutes with a saturated 

 aqueous solution of sodium carbonate; 

 afterwards add some drops of the diazo 

 reagent and stir the liquid well. Ob- 

 serve in glycerin. (The coloration de- 

 velops rapidly and lasts for some days.) 

 Preparation of the diazo-reagent: into 

 a 50 ml. flask immersed in an ice bath, 

 pour 1.5 ml. of a sulphanilic acid solu- 

 tion (dissolve 0.9 g. of pure sulphanilic 

 acid in 9 ml. of concentrated HCl and 

 add water to 100 ml.); add 1.5 ml. of a 

 5% aqueous solution of NaN02, shaking 

 the flask meanwhile. After 5 minutes 

 in the ice bath add, also while shaking, 

 another 6 ml. of nitrite. After 5 min 

 utes fill up to 50 ml. with cooled dis- 

 tilled water. The reagent must be 

 prepared everj^ day and kept in the ice 

 chest. 



"The reaction gives an orange or yel- 

 low color with the histidine and the 

 tyrosine of the proteins." 



Dichlorofluorescein. Structure of, Milligan, 

 R. F. and Hope. F. J., J. Am. Chem. 

 Soc, 1945, 67, 1507-1508. 



Dientamoeba fragilis. Technique of stain- 

 ing and points to be considered in diag- 

 nosis (Hood, M., J. Lab. & Clin. Med., 

 1939-40, 25, 914-918). 



Diethylene Dioxide = Dioxan. 



Differential Leucocyte Count, statistical 

 study of uniformity in (Klotz, L. F., 

 J. Lab. & Clin. Med., 1939, 25, 424-434). 



Diffraction Methods for measuring diameter 

 of red blood cells (Haden, R. L., J. 

 Lab. & Clin. Med., 1937-38, 23, 508-518). 



Digitonine reaction of Windaus for free 

 cholesterol. This has been adapted to 



histochemical use by Brunswick and 

 by Leulier and Noel (A., and R., Bull. 

 d'Hist. Appl., 1926, 3, 316-319). Lison 

 (p. 211) recommends a slight change. 

 Immerse frozen sections of formalin 

 fixed tissue in 0.5% digitonine in 50% 

 ale. for several hrs. Rinse in 50% ale, 

 then in water and mount in Apathy's 

 syrup or glycerin gelatin. With 



crossed nicols (polarizing microscope) 

 one observes appearance of needles or 

 rosettes of the complex cholesterol- 

 digitonide. To resolve this complex 

 stain with sudan. The esters will color 

 and lose their birefringence while the 

 cholesterol will remain uncolored and 

 retain birefringence. 



Di Nitrosoresorcinol test for iron, see Iron. 



Diotrast, trade name for an organic iodine 

 preparation recommended by Gross, 

 S. W., Proc. Soc. Exp. Biol. & Med., 

 1939, 42, 258-259 for injection into 

 common carotid with later x-ray photo- 

 graphs of the vascular tree. 



Dioxan is diethylene dioxide. It mixes 

 with water, ethyl alcohol, many clearing 

 agents and paraffin (slightly). McClung 

 (p. 39) recommends its use to replace 

 ordinary agents like xylol. Dio.xan 

 fumes are said to be dangerous to 

 laboratory workers so that it should be 

 used under a hood or in a well ventilated 

 room with container covered when not 

 in use (Magruder, S. R., J. Lab. & Clin. 

 Med., 1937-38, 23, 405-411). 



For fi.xation the following mixtures 

 are recommended (McClung, p. 39) : 

 (1) Sat. aq. picric acid, 5 parts; glacial 

 acetic, 1 part; dioxan, 4 parts. (2) 

 Sat. picric acid in dioxan, 4 parts ; glacial 

 acetic, 1 part; absolute alcohol, 4 parts. 

 Graupner and Weissberger (von H. and 

 A., Zool. .A.nz., 1933, 102, 39-44) suggest: 

 dioxan 80%, methyl alcohol 20%, paral- 

 dehyde 2%, and acetic acid 5%. Sec 

 Clearing, Pituitary. See as ingredient 

 of Lison's glycogen method; al?o dioxan 

 imbedding of Pituitary. 



A method for the dehydration, puri- 

 fication and clarification of dioxan so 

 that its use in tissue technique can be 

 continued has been described bj^ Hall, 

 W. E. B., Am. J. Clin. Path., 1943, 7 

 (Technical Section), 08-100. 



Dipeptidase can be localized in chief cells 

 of stomach. See review of methods 

 (Gersh, I., Physiol. Rev., 1941, 21, 

 242-266). 



Di-Phenyl Methane Dyes. Of these only 

 auramin need be referred to. 



Diphtheria Bacilli. 1. Neisser's slain 



(Stitt, p. 863). A = methylene blue, 

 0.1 gm.; 95% ale, 2 cc; glacial acetic 

 acid, 5 cc. ; aq. dest., 95 cc. B = 

 Bismark brown, 0.2 gm. ; aq. dest. (boil- 

 ing) 100 cc. Dissolve and filter. To 

 stainsmear pouron A,30-60sec. Wash. 



