BISMUTH PIGMENTATION 



42 



BLOOD CELL VOLUME 



24 hrs. to which drop of diluted Castel 

 reagent has been added. To counter- 

 stain color 4 min. with freshly filtered 

 100 cc. nondiluted reagent plus 1 cc. 

 1% aq. light green S F (Hartman-Led- 

 don Co.). 



Method also can be used for study of 

 fresh tissues and gross specimens. Add 

 cone, hydrogen peroxide drop by drop 

 to pigmented area. Decolorization is 

 rapid if bismuth sulfide is present. 

 Wash thoroughly in running water to 

 remove excess hydrogen peroxide. Ap- 

 ply modified Castel reagent to surface 

 and exanaine for orange ppt. See de- 

 scription by authors of distribution of 

 bismuth pigmentation in the tissues 

 and comparison with other pigments. 



Bismutose, a compound of bismuth and 

 albumen which on application becomes 

 concentrated in the area of the Golgi 

 apparatus (Kredowsky, Zeit. f. Zellf., 

 1931, 13, 1). 



Biuret Reaction. Described as follows by 

 Serra, J. A., Stain Techn., 1946, 21, 5-18: 

 Prepare tissue as described under Nin- 

 hydrin Keaction. "The pieces are im- 

 mersed in strong NaOH or KOH solu- 



^ tion in a watch glass and some drops of 

 a 1% aqueous solution of CuS04 are 

 then added with stirring. A blue- 

 violet coloration indicates the pi'esence 

 of peptides or proteins. 



"The reaction is given by the peptide 

 linkage when the peptides are composed 

 of at least three amino acids. The 

 color is more reddish with the simpler 

 peptides. For cj'tological or histologi- 

 cal work, the reaction has the disad- 

 vantage of requiring a strong alkaline 

 reaction, which tends to dissolve the 

 protoplasm. To avoid a serious dis- 

 solution the tissues must be hardened, 

 for instance with formalin (10% for- 

 maldehyde during 24 hours, followed 

 by a thorough washing) . This reaction 

 has also the disadvantage of being in- 

 sensitive." 



Blastomycosis. The differentiation of Zy- 

 monema (Blastomyces) dermatitidis, the 

 cause of blastomycosis, from Crypto- 

 coccus homlnis, the cause of crypto- 

 coccosis or torulosis, is best accom- 

 plished by wet India ink technique of 

 Weidman, F. D. and Freeman, W., 

 J.A.M.A., 1924, 83, 1163. Stir suspected 

 material in a drop of India ink, place on 

 a clean slide and cover. Use a small 

 drop so as to form a thin film. Work 

 rapidly before the ink dries out. In 

 blastomycosis the wall of the organism is 

 thick and presents a double-contoured 

 appearance. Cryptococcus horninis is 

 surrounded by a thick mucoid capsule 

 which, against a dark background, shows 

 up as a clear halo surrounding the fun- 

 gus. Spinal fluid usually dilutes the 



ink making a lighter background. See 

 Fungi. 



Blood. Microscopically considered blood 

 is the field of the hematologist (see 

 Downey's Hematology, N. Y., Hoeber, 

 1938 in 4 volumes). Any conception of 

 the formed elements of the blood is 

 artificial and inadequate unless it is 

 based upon knowledge of their appear- 

 ance and behavior in vivo. To examine 

 circulating blood in the web of a frog's 

 foot is helpful but it is better to use 

 mammals. In the latter, the methods 

 devised by Covell and O'Leary for study 

 of the living Pancreas are recommended 

 for blood cells also. Probably the best 

 technique is that of Sandison for direct 

 examination of contents of small blood 

 vessels and capillaries in transparent 

 chambers inserted into rabbits' ears. 

 Living blood cells can be observed 

 in vitro at high magnification in Tissue 

 Cultures; but, of course, circulation is 

 lacking. 



When blood cells are removed from the 

 body and mounted on slides in approxi- 

 mately isotonic media, they can be 

 studied for a short time before they be- 

 come seriously injured and die. 

 Examination in the dark field and after 

 Supravital Staining may be helpful. 

 It is important in interpreting the 

 results to remember that the conditions 

 are very abnormal, that the cells are 

 often more flattened than in vivo, and 

 that the actual speed of movement is 

 not that seen, but is that observed di- 

 vided by the magnification because the 

 distance travelled per unit of time 

 naturally appears greater than it 

 actually is. The motion picture tech- 

 nique has great potentialities. 



Examination is usually limited to fixed 

 and stained Blood Smears but valuable 

 data can also be secured from sections. 

 Normal values for blood cells during first 

 year of life (Merritt, K. K., 1933, 46, 

 990-1010). For details, see Blood Pro- 

 tein (coagulated). Bone Marrow, Chylo- 

 microns, Erythrocytes, Erythrocyte 

 Counts, Fibrin, Hematoidin, Hemato- 

 porphyrin, Hemofuscin, Hemoglobin, 

 Hemosiderin, Leucocytes, Leucocyte 

 Counts, Lymphocytes, Monocytes, 

 Platelets, Parhemoglobin, Reticulo- 

 cytes, Sulfmethemoglobin. 



Blood Agar, see Bacteria, Media. 



Blood Cell Volume. Dry Evans Blue 

 (Merck) at 100 °C. Dissolve 400-800 

 mg. in 1 liter aq. dest. Put 0.5-1 cc. in 

 tube 3-4 cc. capacity and evaporate to 

 dryness at 70 °C. Collect blood to 

 contain 2.0-2.5 units heparin or 0.2% 

 anunonium oxalate. Centrifuge and 

 transfer 1 cc. plasma to tube containing 

 dye. Remove 0.1 cc. dyed plasma to 

 9.9 cc. saline in photoelectric colorimeter 



