POLAROID 



281 



POLYSACCHARIDES 



rene and 9, 10-dimethyl-l ,2-benzanthra- 

 cene can be determined polarograph- 

 ically (Wawzouek, S., and Laitinen, 

 H. A., J. Am. Chem. Soc, 1942, &4, 

 2365-2368). 



Many other types of organic com- 

 pounds (aldehydes, ketones, acids, 

 nitro nitroso and azo compounds, per- 

 oxides, sugars (ketases) and heterocylic 

 compounds), which can be qualitatively 

 and quantativel}^ determined polaro- 

 graphically are given in a review by 

 Wawzonek (Anal. Chem., 1949, 21, 61- 

 66), and in the books listed above. 



Polaroid. This is a polarizing material 

 made up of extremely minute crystals 

 of quinine sulpliate 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 in 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 bj' 

 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. Literally 

 many colored, but actuallj'^ 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 fKjlychrome 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. 



Polyethylene glycols are also known as 

 Carbowaxes. See Carbo Wax embed- 

 ding. Rinehart, J. F. and Suleiman 

 Abul-Haj, A. M. A. Archiv. Path., 

 1951, 51, 666-669 advise the dehydration 

 and embedding of formation fixed 

 tissues and the staining therein of 

 lipids by Sudan and other dyes. This 

 is a great improvement over the frozen 

 section technique. 



Polysaccharides — Written by R. D. Hotch- 

 kiss. The Rockefeller Institute for 

 Medical Research, New York 21, N. Y. 

 November 14, 1951 — Polysaccharides 

 are oxidized by periodic acid with pro- 

 duction of polyaldehydes which are 

 stained with Schiff's fuchsin-sulfite 

 reagent. Only substances with 1,2- 

 glycol groupings (almost exclusively 

 carbohydrates, which in fixed tissue 

 preparations are chiefly present as 

 polysaccharides, mucins or mucopro- 

 teins) are supposed to react in this way. 

 In the Schiff-aldehyde reactions, it is 

 important to note that the fuchsin 

 combines chemically with the alde- 

 hydic substances (Wieland and Scheu- 

 ing, Ber., 1921, 54, 2527-2555); the dye 

 is presumably therefore fixed at the 

 site of the original polysaccharide. 

 J. F. A. McManus (Nature 1946, 158, 

 202), R. D. Lillie (Bull. Internat. 

 Assoc, Med. Museums, 1947, 27, 23-61), 

 and R. D. Hotchkiss (Arch. Biochem. 

 1948, 16, 131-141) independently dis- 

 covered and described (he periodic acid- 

 Schiff method; the description below 

 is that of Hotchkiss' procedure. 



Solutions: Alcoholic periodic acid: 

 0.4 gm. periodic acid, dissolved in 15 

 cc. aq. dest., add 0.14 gm. cryst. Na 

 acetate, then add 35 cc. alcohol 95%. 

 Reducing rinse: Dissolve 1 gm. KI, 



