POLARIZATION OPTICAL 



198 



PONTACYL CARMINE 6B 



Frey-Wyssling, A., Submikroskopische 

 Morphologie des Protoplasmas und 

 seiner Derivate, Berlin Geb. Borntra- 

 ger, 1938. Schmitt, F. O., The ultra- 

 structure of protoplasmic constituents. 

 Physiol. Rev., 1939, 19, 270, Schmitt, 

 F. O., Tissue ultrastructure analysis: 

 polarized light method. In Glasser's 

 Medical Physics, 1944, p. 1586. See 

 Nerve Fibers, Muscle Fibers. 



Polarized Light is said to be better than 

 Marchi and Sudan III methods for 

 study of myelin degeneration of periph- 

 eral nerves (Prickett, C. O. and Stevens, 

 C, Am. J. Path., 1939, 15, 241-250). 

 Used in study of mitochondria and 

 Golgi apparatus (Monne, L., Pro to - 

 plasma, 1939, 32, 184-192). 



Polarizing Microscope. Any ordinary 

 microscope can be adjusted for crude 

 polarization studies by use of a polarizer 

 and analyser. See Polarization Optical 

 Methods. 



Polaroid. This is a polarizing material 

 made up of extremely minute crystals 

 of quinine sulphate periodide. A nitro- 

 cellulose film containing the crystals 

 all oriented in the same direction can 

 be mounted between sheets of glass 

 with a total thickness fo about 3 mm. 

 See Bourne, p. 26. 



Pollens. The microscopic identification of 

 the different sorts of pollen, especially 

 the allergens, does not involve any 

 complicated technique. From a good 

 textbook, Feinberg, S. M., Allergy in 

 Practice. Chicago, The Year Book 

 Publishing Co., 1944,798 pp., one is first 

 guided by data on pollens likely to be 

 in the atmosphere at the particular 

 season and in the special locality. The 

 next step is to spread on microscopic 

 slides very thin films of white petrola- 

 tum. Then expose, for measured time, 

 these ig a horizontal position coated 

 side up protected by a suitable covering 

 from rain but not so as to interfere with 

 access of air. Examine directly by 

 direct illumination or in dark field. If 

 staining is necessary apply Calberla's 

 solution as described by Gay, L. N., 

 Curtis, H. and Norris, T., Bull. Johns 

 Hopkins Hosp., 1941, 68, 179-189 (glyc- 

 erin 5 cc; 95% ale, 10 cc; aq. dest., 

 15 cc; sat. aq. basic fuchsin, 2 drops). 

 Most important is detailed microscopic 

 comparison of the grains observed with 

 the illustrations in the following mono- 

 graph: Wodehouse, R. P., Pollen 

 Grains. New York : McGraw-Hill Book 

 Co., 1935. 



Poly-Azo Dyes. Chlorazol black E, sudan 

 black B. 



Polychromatic Erythroblasts, see Erythro- 

 cytes, developmental series. 



Polychrome Methylene Blue. Literallj' 

 many colored, but actually in this case 



two colored. It is a methylene blue 

 which contains, in addition to the blue 

 itself, large amounts of azures especially 

 A and B . These are redder than methy- 

 lene blue and are partly responsible for 

 the metachromatic staining (G. meta, 

 beyond -\- chroma, color) given by 

 polychrome methylene blue. The color 

 is beyond and different from the simple 

 blue by reason of its marked reddish 

 tint. It is usually better to purchase 

 the polychrome methylene blue rather 

 than to make it. If it has to be made 

 dissolve 1 gm. methylene blue in 100 

 cc. 0.5% aq. NaHCOj; place in steam 

 sterilizer 1| hrs.; cool and filter (Mc- 

 Clung, p. 334). It should be a good 

 methylene blue. Goodpasture's (E. 

 W., J.A.M.A., 1917, 69, 998) recipe for 

 polychrome methylene blue is : Boil 400 

 cc. aq. dest. + 1 gm. methylene blue and 

 1 gm. potassium carbonate for 30 min. 

 Cool and add 3 cc. acetic acid and shake 

 dissolving ppt. Boil gently down to 

 200 cc. volume (5 min.). Cool. Eosi- 

 nates spectra and staining potency 

 (Lillie, R. D. and Roe, M. A., Stain 

 Techn., 1942, 17, 57-63). See also 

 Lillie, R. D., Stain Techn., 1942, 17, 

 97-110 for acid oxidation methods of 

 polychroming. 



Polyvinyl Alcohol, macromolecular proper- 

 ties (Heuper, W. C, Arch. Path., 

 1942, 33, 271). Use in preparing tissues 

 for staining with Sudan III (Lubkin, 

 V. and Carsten, M., Science, 1942, 95, 

 634). 



Ponceau B, see Biebrich Scarlet, water 

 soluble. 



Ponceau R, RG, G, 4R, 2RE, NR, J, FR, 

 GR, see Ponceau 2R. 



Ponceau 2R (CI, 79). — Brilliant ponceau G, 

 lake ponceau, new ponceau 4R, ponceau 

 R, RG, G, 4R, 2RE, NR, J, FR, GR, 

 scarlet R, xylidine ponceau 3RS. — 

 An acid mono-azo dye which may be the 

 ponceau de xylidine called for in 

 Masson's Trichrome Stain. 



Ponceau S (CI, 282) of National Aniline 

 Division of Allied Chemical and Dye 

 Corporation is used by Leach, E. H., 

 Stain Techn., 1946, 21, 107-119 in Cur- 

 tis' Substitute for Van Gieson Stain. 



Ponder's Stain for Diphtheria Bacilli, 

 which see. 



Ponsol Red 5 GK (CI, 1131) and Ponsol Red 

 AFF, both of DuPont are referred to by 

 Emig, p. 64. 



Pontachrome Brown MW (CI, 101) of Du- 

 Pont, a monoazo mordant dye, light 

 fastness 4, action of which on blue green 

 algae is described (Emig, p. 31). 



Pontachrome Orange R (CI, 415) of DuPont, 

 a direct disazo dye of color fastness 5. 

 Gives fugitive colors only (Emig, p. 40j. 



Pontacyl Carmine 6B (CI, 57), DuPont, is an 

 acid, monoazo dye which colors sections 



