MS 23.21-MS 30 



METAL STAINS 



541 



23.21 Muschenkoff test. 1907 Bohm and Oppel Bohm and Oppel 1907, 267 



REAGENTS REQUIRED: A. 2% potassium dichromate; B. 20% formic acid; C. 0.5% gold 



chloride; D. 0.1% acetic acid 

 method: [small pieces] -^ A, \ month — > wash — * B, 15-20 mins. -^ rinse — > C, in dark, 



30 mins. -* D, in light, till reduced — » M 10 mountant 

 RECOMMENDED FOR: ncrvc endings. 



23.21 Upson test. 1896 Kahlden and Laurent Kahlden and Laurent 1896, 160 



REAGENTS REQUIRED: A. 1% potasslum dichromatc; B. 1% gold chloride in 2% hydro- 

 chloric acid; C. 10% potassium hydroxide; D. water 75, sulfuric acid 10, ADS 12.2 

 Lugol (1905) 15, ferric chloride 0.3 

 method: [fresh spinal cord] -^ A, 4-6 mnths., in dark—* [2-3 mm. thick slabs]—* 

 rinse — * 50% ale, 2-3 days — » 95% ale. tUl green, 2-4 wks. -^ [celloidin sections] — > B, 

 2 hrs. — * wash -^ C, 30 sees. — * D, till reduction complete -* wash -^ balsam, via 

 usual reagents 

 RECOMMENDED FOR: axis Cylinders. 



23.21 Viallane 1883 test. Lee 1905 Lee 1905, 250 



REAGENTS REQUIRED: A. 1% osmic acid; B. 25% formic acid; C. 0.02% gold chloride; 



D. 25% formic acid 

 method: [arthropod tissues] -^ A, until light brown -^ B, 10 mins. -^ C, 24 hrs. in dark 

 -^ 24 hrs. in light 



23.3 Cytological Methods 



23.3 Beams test. 1930 Guyer Guyer 1930, 150 



reagents required: A. water 100, gold chloride 0.2, acetic acid 0.3; B. 5% sodium 

 thiosulfate 



method: [3 M sections of F 1360.0010 Brouba 1930 material]—* water—* A, till differ- 

 entiated -^ wash — * 5, 2 mins. — * wash — * balsam, via usual reagents 



recommended for: Golgi bodies in glands. 



23.4 Other Methods 



23.4 Kupffer 1876 1780, 12 :353 



reagents required: A. 0.05% chromic acid; B. 0.01% gold chloride in 0.01% hydro- 

 chloric acid 



method: [sections by freezing technique of fresh tissue] -^ A, 15 mins. — * rinse — * B, in 

 shade, till violet — > wash -^ glj^cerol 



recommended for: connective tissue in liver 



23.4 Kupffer 1899 1780, 5:219 



reagents required: A. 0.01% chromic acid; B. water 100, 40% formaldehyde 0.01, 



gold chloride 

 method: [frozen sections of fresh liver] — * A, 10 mins. -^ B, 30 hrs. — * wash — * balsam, 



via usual reagents 

 recommended for: demonstration of astrocytes in liver. 



MS 30 Silver 



The techniques of silver staining are 

 commonly compared to those of pho- 

 tography, though the analogy cannot jus- 

 tifiably be maintained, save in the case 

 of the original process by Simarro (Gat- 

 enby and Painter 1937, 477). Photography 

 consists essentially in the reduction to me- 

 tallic silver of particles of silver bromide, 

 maintained in a colloidal environment, 



and which have been rendered unstable 

 through the absorption of photon energy. 

 Simarro impregnated living forms with 

 solutions of potassium bromide and then 

 sensitized them, as in the photograpliic 

 methods of his day, by immersion in a 

 solution of silver nitrate. Parts of these 

 impregnated animals were then sectioned 

 and exposed to light; such silver bro- 



