POLYVINYL ALCOHOL 



283 



PORPHYRINS 



Leblond (Amer. J. Anat. 1950, 86, 1-50) 

 has surveyed the staining of rat tissues 

 rather thoroughly. A discussion of the 

 chemical mechanism and tests of many 

 isolated substances were provided by 

 Hotchkiss (loc. cit.). 



Uses and appUcations: The following 

 substances have been stained with the 

 periodic-acid-Schiff methods: glycogen, 

 starch, mucins, hyaluronic acid, cell- 

 ulose, chitin, agar, amyloid, reticulin, 

 kerasin, colloid of the thj'roid and hypo- 

 physis, collagen. Structures or regions 

 revealed have included basement mem- 

 branes, cartilage matrix, ground sub- 

 stance of connective tissue, hyaline 

 casts, hyaline of arteriosclerosis, ovar- 

 ian cj'st and follicle fluid, lens capsule, 

 Descemet's membrane, collagenous re- 

 ticulum, chromaffin, brush border of 

 the renal tubules, elements in the mi- 

 totic figures of tumor tissue, zymogen 

 granules, mold mycelium, flagella in 

 certain algae, plant cell walls, sperm 

 acrosomes. The stain is particularly 

 convenient for demonstrating vividly 

 the pathogenic fungi infecting the less 

 intensely staining animal tissues (Klig- 

 man, A. M. and Mescon, H., J. Bact., 

 1950, 60, 415-421). In a few cases, ma- 

 terial stained in tissues has been corre- 

 lated, with a view to tentative identifi- 

 cation, with such specific glycoproteins 

 as gonadotrophic hormone in the pitui- 

 tary (Catchpole, H. R., Fed. Proc. 

 1947, 6, 88), renin in the kidney 

 (Marshall, J. and Wakerlin, G. E., 

 Fed. Proc. 1949, 8, 106-7), accessory 

 reproductive gland secretion in beetles 

 (Anderson, J. M., Biol. Bull., 1950, 

 99, 49-64), and hyaluronidase in the 

 sperm acrosome (Leutchtenberger, C. 

 and Schrader, F., Proc. Natl. Acad. 

 Sci., 1950, 36, 677-683). 



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 u.sed by Leach, E. II., 

 Stain Techn., 1946, 21. 107-110 in Cur- 

 tis' Substitute for Van Gieson Stain. 



Ponceau de Xylidine. The difficulty is 

 that the Fench "ponceau de xylidine" 

 cannot be secured. It appears to be 

 similar to ponceau 2R (C.I. 79) but the 

 latter does not give regularly good re- 

 sults. Lillie (R. D., Stain Tech., 1940, 

 15, 17-22) suggests the following sub- 

 stitutes for ponceau de xylidine: azo- 

 fuchsin 3B (C.I., 54), nitrazine yellow 

 and biebrich scarlet (C.I., 280)". See 

 the Biebrich Scarlet and Picro-Anilin 

 Blue method of Lillie. Sec Masson's 

 Trichrome. 



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. 40). 



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

 acid, monoazo dye which colors sections 

 bluish fuchsia darkened by mordanting 

 with potassium bichromate. Not im- 

 portant in microtechnique (Emig, 

 p. 30). 



Pontacyl Carmine 2 G (CI, 31)— Made by 

 DuPont. Light fastness 3. More in- 

 tense color than azofuchsin. Action on 

 fungous myoelia (Emig, p. 29). 



Pontamine Fast Pink BL (CI, 353), a disazo 

 direct dye of light fastness 3 to 4. Use 

 in acid and alkaline solutions as stain 

 for plant tissues and algae are described 

 (Emig, p. 39). 



Pontamine Sky Blue 5BX, see Niagara Blue 

 4B. Use in measurement of lymph flow 

 (McMaster, P. D., J. Exper. Med., 1937, 

 65, 373-392) . 



Poppy Seed Oil, reactions in tissue to fat 

 stains after various fixations (Black, 

 C. E., J. Lab. & Clin. Med., 1937-38, 

 23, 1027-1036). 



Porphyrins. — Written by Frank H. J. Figge, 

 Dept. of Anatomy, Universitj' of Marj'- 

 land Medical School, Baltimore, Md. 

 October 10, 1951 — There is no specific 

 histo-chemical reaction for porphyrins, 

 but Watson, C. J. and Clark, W. O., 

 Proc. Soc. Exp. Biol. & Med., 1937, 

 36, 65-70 believe that it is the proto- 

 porphyrin in reticulocytes that stains 

 with brilliant cresyl blue. See Reticu- 

 locytes. 



Watson and his workers and other in- 

 vestigators have more recently modified 

 their views regarding this point (Wat- 

 son, C. J., Blood, 1946, 1, 99-120) 

 Keller and Seggel had demonstrated 

 that the porphyrin containing cells 

 were not identical with reticulocytes 



