SULFHYDRYL GROUPS 



234 



SULPHUR 



obtained good results with a fixation in 

 10% neutral formaldehyde during 2-15 

 hours at room temperature. A more 

 prolonged action of this fixative also 

 hinders the reaction; it is recommended, 

 therefore, that if possible 2-4 hours of 

 fixation be used. 



"The results of the reaction have 

 different meanings according to the 

 fixation, washings, etc., because the 

 glutathione is partly soluble. When 

 the tissues are treated several times 

 with a 10% solution of trichloroacetic 

 acid for 15 minutes, the glutathione is 

 dissolved and only "fixed", that is, pro- 

 teic sulfhydryl groups remain in the 

 preparation. It is still possible not 

 only to demonstrate the existing SH 

 groups but also to reduce SS groups to 

 SH groups, by means of a pre -treatment 

 of the materials with a solution of 10% 

 KCN for 10 minutes in a small stoppered 

 bottle (the cyanide solution can be 

 weakly alkalinized with potassium hy- 

 droxide, to make its use safe). 



"The reaction has been recognized as 

 well localized, but in case of doubt a 

 test of secondary impregnation can be 

 made in the way described for the 

 ninhydrin." 

 Sulfmethemoglobin, a greenish compound 

 of methemoglobin and sulphur often 

 encountered in abdominal walls of 

 cadavers, but it may be present in 

 blood where it can be diagnosed by 

 spectroscopic examination (Mallory, 

 p. 135). 

 Sulfonamides. Great importance of sulfa 

 drugs makes their demonstration in 

 tissues useful. Mackee, G. M., Herr- 

 mann, F., Baer, R. L. and Sulzberger, 

 M. B., Science, 1943, 98, 66-68; J. Lab. 

 & Clin. Med., 1943, 28, 1642-1649. 



Fix fresh tissue with dry formalde- 

 hyde gas and visualize sulfa compounds 

 as orange precipitates in frozen sections 

 treated with p-dimethylaminobenzalde- 

 hyde in acid alcohol solution. In at- 

 tempting to identify sulfonamides 

 microscopically in urinary sediments 

 the descriptions and diagrams of the 

 various crystals given by C. J. Gentz- 

 kow and H. A. Van Auken in Simmons 

 and Gentzkow will be helpful, viz. 



Sulfadiazine: (1) free drug, "dark 

 greenish irregularity striated spheres 

 with either fuzzy or clean edges"; (2) 

 acetyl crystals like "sheaves of wheat 

 with eccentric bindings". 



Sulfaguanidine : (1) free drug, rare; 

 (2) acetyl crystals as "thin oblong 

 plates, clear or with fine mesh pattern, 

 often aggregated into cross or star-like 

 clusters". 



Sulfanilamide: (1) free drug as large 

 needles with angle of 106° at ends 



often in sheaves; (2) acetyl crystals 

 similar needles with square ends. 



Sulfapyridine : (1) free drug as stubby 

 prisms; (2) acetyl crystals as "boat- 

 or petal-shaped forms with rounded 

 edges; start angled crystals; bow ties or 

 burrs; and occasionally as large ro- 

 settes." 



Sulphathiazole : (1) free drug rare as 

 flattened or 6 sided crystals with angle 

 at end of 84°; (2) acetyl crystals may 

 resemble those of free drug but with 

 end angles of 136° when they look like 

 wheat sheaves with central binding. 

 These may be swollen suggesting 2 half 

 circles fused at center; striated spheru- 

 lites frequently occur. 



Sulfasuccidine crystals absent be- 

 cause of but slight absorption of this 

 drug from intestine. 



Sulfonphthaleins. These are compounds of 

 phthalic anhydride and ortho-sulfo- 

 benzoic acid. They are most valuable 

 indicators. Examples: brom chlor phe- 

 nol blue, brom cresol green, brom cresol 

 purple, brom phenol blue, brom phenol 

 red, brom thymol blue, chlor cresol 

 green, chlor phenol red, cresol red, 

 metacresol purple, phenol red, thymol 

 blue. 



Sulfur Bordeaux (CI, 1012), Sulfogene Bor- 

 deaux BRN (DuPont) and Sulfur Bor- 

 deaux BCF (NAC) are direct dyes of 

 light fastness 2. Specifications for 

 staining invertebrates and plant tissues 

 are given (Emig, p. 62). 



Sulfur Brilliant Blue (CI, 957), Sulfindone 

 Brilliant Blue CG (NAC), Sulfogene 

 Brilliant Blue 6BS (DuPont), and Sulfo- 

 gene Brilliant Blue 3 GCF (DuPont) 

 are the best blue direct sulfur dyes of 

 color fastness 2, the use of which for 

 staining algae and invertebrates is de- 

 scribed (Emig, p. 61). 



Sulfur Direct Blue (CI, 956), Sulfogene 

 Direct Blue BRS (DuPont), a direct 

 dye of light fastness 2 which does not 

 color blue green algae as intensely or 

 brightly as Sulfur Brilliant Blue, but 

 does present details of cell structure 

 clearly (Emig, p. 61). 



Sulfur Green (CI, 1006), Sulfogene Green 



2 B (DuPont), Sulfogene Brilliant 

 Green 2 G (DuPont) and Sulfur Green 



3 G cone. (NAC), direct dyes of light 

 fastness 2 action of which on plant tis- 

 sues and invertebrates is described 

 (Emig, p. 62). 



Sulfur Orange (CI, 949) and Sulfur Yellow 

 (CI, 948) resemble Sulfur Bordeaux 

 (Emig, p. 61). 



Sulphonal Poisoning. Effect on liver cell 

 mitochondria (Grynfeltt, E., and La- 

 font, R., C. rend. Soc. de Biol., 1921, 

 85, 406-408). 



Sulphur. In inorganic form sulphur is not 



