SECTION TWO 



8. Wash with distilled water. 



9. Differentiate in the phosphomolybdic acid solution for about 

 thirty minutes, controlling by examination under the micro- 

 scope at intervals. 



10. Wash with two changes of distilled water. 



11. Stain collagen in the alizarin viridin for seven minutes. 



12. Drain and blot thoroughly but carefully. 



13. Rinse with 96% alcohol; followed by carbol xylol. 



14. Wash well with two or three changes of xylol, and mount. 



Results: 



Nuclei, dark brown. Muscle and epithelium, pale violet. 

 Erythrocytes and elastic fibres are stained a rich brown, while 

 mucus, collagen are in varying shades of green ; myelin sheaths, 

 pink ; and axis cylinders, dark blue. 



GIEMSA STAIN 



For malarial parasites, rickettsia, etc. 



Solution required: 



Giemsa stain . . . . . . i ml. 



Distilled water, buffered to pH 7-2 20 ml. 



N.B.: This mixture should be freshly prepared 

 immediately before use. 



Technique: 



1. Fix small pieces of tissue in 10% formalin, Regaud or Zenker. 



2. Dehydrate; clear and embed. 



3. Bring down paraffin sections to distilled water in the usual 

 manner. 



4. Stain for eighteen to twenty-four hours in the diluted Giemsa 

 (as above). 



5. Wash in distilled water; differentiate quickly in 0-5% acetic 

 acid until the section is pink ; then wash with distilled water. 



6. Blot and dry in air and mount. 



Results: 



Nuclei are stained dark red ; erythrocytes, pink. Malaria para- 

 sites, bluish red with red chromatin. 



105 



