GLYCOGEN 



142 



GOLD 



chance for displacement of glycogen in 

 the cells. 



See also for glycogen staining of 

 Trachoma inclusions Thygeson, P., Am. 

 J. Path., 1938, 14, 455-462. Glycogen is 

 immobilized in its natural position 

 within the cells by the Freezing and 

 Drying technique (Altmann-Gersh). 

 Compare figures 3 and 4 of Bensley and 

 Gersch (R. R. and I., Anat. Rec, 1933, 

 57, 205-215) showing results by this 

 and other methods. 



A new ammoniacal silver nitrate 

 method for glycogen is described by 

 Mitchell, A. J., and Wislocki, G. B., 

 Anat. Rec, 1944, 90, 261-266. To pre- 

 pare silver solution dissolve 1 gm. silver 

 nitrate in 10 cc. aq. dest. and add 11 

 drops 40% aq. potassium hydroxide. 

 Dissolve ppt. by adding 26% ammonia 

 drop by drop and make up with abs. 

 ale. to 100 cc. Allow to stand over 

 night before use. 



Fix livers of guinea pigs and placentas 

 of same and other animals for 6-12hrs. 

 in sat. picric acid in abs. ale, 90 cc. 

 and neutral formaldehyde, 10 cc. 

 Wash in abs. ale. several times likewise 

 in chloroform and abs. ale. Transfer 

 to chloroform and embed in paraffin. 



Place sections in 0.25% aq. potassium 

 permanganate, 5-10 min.; rinse in aq. 

 dest. 1-2 min., decolorize in 5% aq. 

 oxalic acid, 5 min. and rinse again in aq. 

 dest. Place in 2% aq. silver nitrate, 

 12-24 hrs., transfer to ammoniacal sil- 

 ver nitrate, 15-30 min., rinse in 4% 

 neutral formalin, 5-20 sec. and in run- 

 ning water, 1 min. Fix in 5% aq. 

 sodium thiosulphate, 5-10 min. After 

 washing in running water, 1 min., 

 counterstain in paracarmine (Mayer), 

 dehydrate, clear in xylol and mount in 

 balsam. Glycogen, dense black corre- 

 sponds with that shown by Bauer- 

 Feulgen technique. Excellent illus- 

 trations. 



The recently developed techniques 

 of Gomori (Am. J. Clin. Path., 1946, 16, 

 177) and Hotchkiss (Arch. Biochem., 



1948, 31, 131) can be used on tissue sec- 

 tions or blood smears (Gibb, R. P., and 

 Stowell, R. E., Blood, J. Hematology, 



1949, 4, 569-579). The evaluation of 

 methods for the histochemical study of 

 glycogen by Carpenter, A.M., Polon- 

 sky, B. and Mesiten, M. U. (Arch. 

 Path., 1951, 51, 480-485) may be help- 

 ful. 



The best way to separate out glycogen 

 en masse is by centrifugal isolation as 

 employed by Lazarow, A. (Anat. Rec, 

 1942, 84, 31-50; Biol. Symposia, 1943, 

 10, 9-26) for suspensions of fragmented 

 liver cells. 



Colorimetric methods for glycogen 



may afford valuable evidence. See 

 Boettiger, E. G. (J. Cell. Comp. 

 Physiol., 1946, 27, 1-8) and Van Wagten- 

 donk, W. J., Simonsen, D. H. and Hack- 

 ett, P. L. (J. Biol. Chem., 1946, 163, 

 301-306) and the critical discussion by 

 Click, p. 247. See Heatley, N. G. and 

 Lindahl, P. E. (Proc. Roy. Soc, B, 

 1937, 122, 395-402) for separation of 

 desmo- and lyoglycogen. 



Glycol Stearate. As an imbedding medium 

 (Cutler, O. L, Arch. Path., 1935, 20, 

 445-446). Pass up through alcohols to 

 equal parts 95% ale. and glycol stearate 

 in incubator at 56''C. 12-24 hrs. Pure 

 glycol stearate at 56°C. 24 hrs. Imbed 

 as in paraffin. 



Glucuronidase. An enzyme, widespread in 

 occurrence in the mammalian organism, 

 which hydrolyzes esters of glucuronic 

 acid. Glucuronides are important de- 

 toxification products. Chemical meth- 

 ods for identification of glucuronidase 

 are available (see Fishman, W. H., 

 Chapter 18, The Enzymes New York: 

 Academic Press). 1950 Vol. 1, part 1, 

 pp. 635-652, Friedenwald, J. S. and B. 

 Becker (J. Cell, and Comp. Physiol., 



1948, 31, 303-309) have described a 

 method for localizing glucuronidase on 

 tissue sections, and Seligman, A.M., 

 M. M. Nachlas, L. H. Manheimer, O. 

 M. Friedman and G. Wolf (Ann. Surg., 



1949, 130, 333-341) describe a method 

 involving the hydrolysis of the beta 

 glucuronide of beta naphthol. The 

 liberated naphthol is converted to a 

 dye by diazotization. 



Glyoxal. As substitute for formaldehyde 

 in tissue fixation (Wicks, L. F. and Sunt- 

 zeff, v.. Science, 1943, 98, 204; Stowell, 

 R. E. and Stokes, J. M. J. Tech. Meth. 

 and Bull. Internat. Assoc. Med. Mu- 

 seums, 1944, 24, 25-30). Concentra- 

 tions 2-6% produce less shrinkage and 

 give better cytoplasmic preservation 

 than 4% formaldehyde. Glyoxal is 

 only recommended as general substi- 

 tute for formaldehyde when latter is 

 not available. 



Gmelin's test for bile pigments. On addi- 

 tion of nitric acid containing a little 

 nitrous acid, color changes to green, 

 then red and finally blue observable 

 under microscope. 



Gold, microchemical detection of: 1. Method 

 of Borchardt. Modified by Michaelis, 

 O., Biochem. Zeit., 1930, 225, 478-488. 

 Treat sections of formalin or alcohol 

 fixed tissues for 15 min. in a boiling 

 water bath or for 12-24 hrs. at 40 °C. 

 with 5% aq. silver nitrate. Remove 

 ppt. from section with 20% aq. nitric 

 acid. Gold appears as black granules 

 (Lison, p. 100). 

 2. M.ethod of Okkels, H., C. rend. 



