BUFFERS 



48 



CADMIUM 



Details concerning numerous buffers are 

 given by Clark, W. M., The Determina- 

 tion of Hydrogen Ions. Baltimore: 

 Williams & Wilkins, 1928, 717 pp. 

 French, R. W., Stain Techn., 1930, 5, 

 87-90 (see correction, 1932, 7, 107-108) 

 recommends Sorensen's phosphate mix- 

 tures and Palitzsch's borax-boric acid 

 mixtures each over certain ranges of pH. 

 He emphasizes the fact that the addition 

 of buffer salts is known to have a decided 

 influence in some cases on the behavior 

 of the dyes irrespective of pH. See 

 also Clark and Lubs Buffers. 



Petrunkevitch, A., Anat. Rec, 1937, 

 68, 267-280 explains that aqueous solu- 

 tions of stains at certain pH's are more 

 selective than alcoholic ones and that 

 the greatest differentiation is obtained 

 with the former ones with pH suit- 

 ably adjusted by addition of HCl or 

 NaOH. Next in desirability come 

 stains dissolved in acetate, phosphate 

 and borate buffers. Citrate buffers are 

 in his experience less suitable because a 

 more diffuse staining results while 

 phthalate buffers should not be used. 

 He gives specific directions for the 

 preparation of solutions at pH of maxi- 

 mum staining of acid fuchsin, aniline 

 blue, aurantia, benzoazurine, eosin Y, 

 light green, metanil yellow, methylene 

 blue, orange G, toluidin blue, Wrights 

 stain and eosin methylene blue. 



For safranin O, see Sawyer, C. H., 

 Stain Techn., 1940, 15, 3-7 and for hema- 

 toxylin, malachite green and eosin Y, 

 Craig, R. and Wilson, C, ibid, 1941, 16, 

 99-109. Levine, N. C, ibid, 1940. 

 15, 91-112 contributes useful data on 

 buffered stains in relation to isoelectric 

 point of cell components. Obviously 

 the maximum intensity of staining 

 depends not only on pH but also on 

 properties of substances stained and 

 their treatment from beginning to end 

 of the technique. Lillie, R. D., Stain 

 Techn., 1941, 16, 1-6 employed Mcll- 

 vaine citric buffers in order to improve 

 Romanowsky staining (see Toluidine 

 Blue Phloxinate) after various fixatives. 

 See McJunkin-Haden BufiTer. Use of 

 buffered thionin as Nissl stain (Windle, 

 W. F., Rhines, R. and Rankin, J., Stain 

 Techn., 1943, 18, 77-86). For buffering 

 in connection with silver impregnation 

 see Davenport, H. A., Mc Arthur, J. 

 and Bruesch, S. R., Stain Techn., 1939, 

 14, 21-26; Silver, M. L., Anat. Rec, 

 1942, 32, 507-529. When accuracy is 

 essential check the actual pH of the 

 solution to which buffers have been 

 added by the glass electrode method 

 which anyone can learn to use in a few 

 hours and which gives the answer very 

 quickly. See Hydrogen Ion Indicators. 



Bundle of His, see Todd, T. W., Cowdry's 

 Special Cytology, 1932, 2, 1173-1210. 



Burns. Methods of experimental produc- 

 tion, vital staining with trj'pan blue, 

 and histological changes (Ham, A. W., 

 Ann. Surg., 1944, 120, 689-697. 



Butter Fat, reactions in tissue to fat stains 

 after various fixations (Black, C. E., 

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

 1027-1036). 



Butyl Alcohol, see n-Butyl and Tertiary 

 Butyl. 



Buzaglo's Connective Tissue Stain. (Bu- 

 zaglo, J. H., Bull. d'Hist. Appl., 1934, 

 11,40-43). This method is intended to 

 replace that of Van Gieson. Solutions 

 required: (1) Gallocyanin (Hollborn, 

 2264). Boil 0.1 gm. iu 100 cc. 5% aq. 

 chrome alum for 10 min. After cooling 

 make up to 100 cc. with aq. dest., filter 

 and add a little formalin to filtrate. (2) 

 Orcein (Hollborn, 2466). Dissolve 1 

 gm. in 100 cc. acid alcohol (70% alcohol, 

 100 cc. -f 1 cc. hydrochloric acid stand- 

 ard). (3) Acid alizarin blue (Hollborn, 

 2559). Boil for 10 min. 5 gm. iu 100 cc. 

 10% aq. aluminum sulphate. After 

 cooling make up to 100 cc, filter and add 

 formalin. (4) Alizarine-viridine (Holl- 

 born, 2035). Dissolve 0.2 gm. in 100 

 cc. aq. dest. acidulated to pH 5.8 with 

 hydrochloric acid. He advises fixation 

 in formalin, Maximow's fluid, Susa or 

 Hoffker (of which he does not give 

 composition). Pass sections (presum- 

 ably paraffin) down to aq. dest. Stain 

 nuclei in gallocyanin as deeply as pos- 

 sible 5 times, 24 hrs. Rinse twice in 

 aq. dest. Stain elastic fibers in orcein, 

 then aq. dest., 3 times, 5 min. Stain 

 muscle in acid alizarin blue, 7 min., aq. 

 dest. twice. Differentiate in 5% aq. 

 phosphomolybdic acid 25-30 min., aq. 

 dest. twice. Stain collagen in alizarine 

 viridine 7 rain. Blot with 4 layers filter 

 paper. 95% ale 96% ale." Carbol- 

 xylol, 2 changes xylol. Balsam. Nu- 

 clei, dark blue ; elastic fibers, red brown ; 

 muscle and epithelium, pale blue violet ; 

 collagen, mucus, cartilage, shades of 

 green; myelin sheaths, rose; axis cylin- 

 ders, dark blue; erythrocytes, red 

 brown. 



Cadmium. The chloride is employed in 

 fixation of Golgi apparatus prior to silver 

 impregnation (Aoyama, F., Zeit. wiss. 

 mikr., 1929, 46, 489-491). See comment 

 by Baker (Bourne, p. 19) on this and 

 use by Ciaccio of cadmium nitrate to 

 render phospho- and galactolipines less 

 soluble. Bourne (p. 106) refers to 

 Joyet-Lavergne's claim that cadmium 

 lactate reacts with glutathione in the 

 cell producing a cadmium glutathione 

 compound which is microscopically 

 visible. 



