SECTION TWO 



6. Differentiate by dipping into 90% alcohol then examining 

 rapidly under the microscope. Repeat this process until the cell 

 nuclei are well brought out, stained clear bright red. 



7. Dehydrate by rinsing quickly in absolute alcohol ; then clear 

 in xylol and mount in balsam. 



Results: 



Elastic fibres are stained dark to reddish brown; cell nuclei, 

 bright red; ground substance of hyaline cartilage, yellow. 



ORCEIN - GIEMSA STAIN 

 For sjrphilitic tissue, particularly dermatological specimens 



Solutions required: 



A. Orcein (Unna-Tanzer) : 

 Orcein 



Alcohol 70% 

 HCl, concentrated 



B. Absolute alcohol 

 HCl, concentrated 



0-5 gm. 

 100 ml. 

 0*6 ml. 



100 ml. 

 0'5 ml. 



C. Giemsa stain . . . . . . 0-25 ml. 



Distilled water . . . . . . 100 ml. 



Note: Solution C should be prepared freshly, as 

 required, from Giemsa stain. 



D. Absolute alcohol . . . . 100 ml. 

 Eosin 1% alcoholic . . . . i ml. 



Technique: 



1. Paraffin sections are brought down to 70% alcohol. 



2. Stain for one half to one hour in Solution A ; then rinse for 

 two to five minutes in distilled water. 



3. Wipe off excess water; dip into 95% alcohol for a few sec- 

 onds; then decolorize with absolute alcohol for five to twenty- 



177 



