MEDICAL AND BIOLOGICAL STAINING TECHNIQUES 



B. Wright's stain. 



C. Acetic acid, o-o8% aqueous. 



Technique: 



1. Fix pieces of tissue in Solution A for sixteen to forty-eight 

 hours. 



2. Dehydrate in the usual ascending grades of alcohol; clear 

 and embed in paraffin wax. 



3. Fix sections, not exceeding 5// in thickness to slides; remove 

 wax with xylol ; pass through descending grades of alcohol down 

 to neutral distilled water. 



4. Stain for three to five minutes in a freshly prepared mixture 

 consisting of one volume of Wright's stain and two volumes of 

 neutral distilled water, in a stoppered staining jar. 



5. Rinse with neutral distilled water. 



6. Differentiate with the acetic acid solution, controlling by 

 examination under the microscope, until the protoplasm of the 

 cells is pink, and only nuclei are blue. 



7. Wash with neutral distilled water. 



8. Dehydrate quickly with absolute alcohol; clear in xylol; 

 mount in Cristalite. 



Results: 



Erythrocytes, yellowish red. Polymorphonuclears, dark purple 

 nuclei, reddish violet granules, pale pink cytoplasm. Eosinophiles, 

 blue nuclei, red to orange-red granules, blue cytoplasm. Baso- 

 philes, purple to dark blue nuclei, dark purple to black granules. 

 Lymphocytes, dark purple nuclei, sky blue cytoplasm. Platelets, 

 violet to purple granules. Malarial parasites and Leishmanial 

 chromatin, red; cytoplasm, blue. Trypanosomes : chromatin, 

 red. 



Note: The timing of the staining either before or after dilution 

 may be altered to suit individual requirements. 



Staining effects similar to Giemsa are obtained by staining for 

 ten minutes in Wright's stain diluted with four times its volume of 

 distilled water buffered to pH 6-5. 



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