FURFURAL 



136 



G ALLOC YAN IN -CHROMALUM 

 STAINING 



a clean slide. This should be done 



fently to avoid destruction of the 

 ungous growth. The fungus is teased 

 apart gently in one of several fluids 

 such as water, alcohol, alcohol and 

 glycerine (equal parts) or other mount- 

 ing fluids. Water has a high surface 

 tension and causes disruption of the 

 growth; while alcohol evaporates rap- 

 idly and must be replaced. The 

 following solution serves well : 2% 

 potassium acetate, 50 cc; glycerin, 20 

 cc; and 95% alcohol, 30 cc. The 

 preparation is examined with reduced 

 light. The preparations may be stained 

 using one of the several methods listed : 

 lactophenol-cotton blue ; methylene 

 blue-glycerin; or Giemsa-glycerin. See 

 Chorioallantoic Membrane, Actlno- 

 mycetes. 



Furfural. Has been suggested but is not 

 recommended as substitute for formal- 

 dehyde (Stowell, R. E. and Stokes, 

 J. M., J. Tech. Meth. and Bull. In- 

 ternal. Assoc. Med. Museums, 1944, 24, 

 25-30). 



Fuscin (L. fuscus, dusky), a dusky pigment 

 of retinal epithelium usually present 

 in crystalline formations made up of 

 albuminous cores, which determine 

 their shape, plus the adsorbed fuscin 

 material. A relationship to melanin 

 is debated but the pigment is very 

 resistant to chemical attack. It can, 

 however, be bleached completely when 

 exposed to light in vitro. For details 

 see Arey, L. B. in Cowdry's Special 

 Cytology, 1932, 3, 1218. 



Fustics. "Young" fustic is a stain obtained 

 from the smoke tree, Rhus cotinus of 

 West Indies and South America giving 

 colors from bright yellow to dark olive 

 now seldom used by dyers. "Old" fus- 

 tic is obtained from a tree of the mul- 

 berry family, Chlorophora tinctora, 

 which grows in the same countries. It 

 is chiefly employed for woolens giving 

 shades of lemon and old gold (Leggett, 

 W. F., Ancient and Medieval Dyes. 

 Brooklyn: Chemical Publishing Co. 

 Inc., 1944, 95 pp.). 



Gadolinium see Atomic Weights. 



Galliamine Blue (CI. 894) can be employed 

 in place of hematoxylin as an iron lake 

 stain for nuclei. 



Gallein (CI, 781), a mordant dye of light 

 fastness 1. Use as solution 0.5 gm. in 

 100 cc. of either 1% aq. anmionium 

 acetate or 0.1% sulphuric acid. Small 

 invertebrates should be previously 

 mordanted, 30 min. in 1% aq. ferric 

 ammonium sulpha e and rinse in aq. 

 dest. before staining for 1 to 2 min. in 

 the solution at 50°C. Color blue black. 

 If copper sulphate is employed for mor- 

 dant color is hematein purple. In 



paraffin sections of animal tissues nuclei 

 color blue black in 15 to 20 sec. at 50°C. 

 Directions are also given for plant tis- 

 sues and Blue-green algae (Emig, p. 

 54-55). 

 Gallium, see Atomic Weights. 

 Gallocyanin-Chromalum Staining of Baso- 

 philic Cell Structures — Written by 

 Ldrus Einarson. Normal-Anatomisk 

 Institut. Aarhus Universitet, Aarhus, 

 Denmark. February 27, 1951. — Baso- 

 philia is an essential property common 

 to some most important cell structures, 

 and the study of the nature as well as 

 the attainment of a method for quanti- 

 tative estimation of basophily have 

 been among the outstanding general 

 problems in histology and cytology. 

 Here, the nerve cells make an especially 

 favourable object on account of their 

 high degree of cytoplasmic basophily 

 due to the Nissl substance, which con- 

 tains nuclein, acid and basic proteins 

 respectively (Einarson L. J. comp. 

 Neur., 1935, 61, 101-133). 



An accurate estimation of basophily 

 can be achieved by staining with dis- 

 solved colour lakes of some synthetic 

 dye-stuffs (Ranvier, 1875; Grenacher, 

 1879; Rawitz, 1896; Becher, 1921), and 

 the staining by gallocyanin-chromalum 

 affords the most accurate representative 

 of this principle of staining by inner- 

 complex dye-metal salts (Einarson, L., 

 Acta path. & Microbiol. Scand., 195, 

 28,82-102). 



The staining solution is made as fol- 

 lows: 5 gm. chromalum puriss. is dis- 

 solved in 100 cc redistilled water, then 

 0.15 gm. gallocyanin (Griibler-HoU- 

 born or Nat. Aniline Division, New 

 York) is added and the whole is mixed 

 by shaking the bottle. The mixture is 

 warmed up gradually and boiled for 5 

 min. After cooling at room tempera- 

 ture, filtration through filter paper and 

 addition of redistilled water through 

 the filter until the volume again is 100 

 cc, the solution is ready for use; its 

 pH is 1.64. Staining time is 48 hrs at 

 room temperature. After staining 

 washing in aq. dest., alcohols, xylol 

 balsam. 



The process by which the lake is 

 formed consists in the formation of a 

 soluble lake-cation (reddish), a slightly 

 soluble lake-sulphate (blue) and a non- 

 soluble lake-hydroxide; the latter is 

 formed by an inmiediate hydrolysis of 

 some of the lake under formation. 

 After the solution has been prepared 

 no further hydrolysis occurs until 4-5 

 weeks later (late hydrolysis), and a 

 gradual sedimentation of lake-hydrox- 

 ide takes place; at the same time the 

 staining power of the solution be- 



