STAINING, PRACTICAL AND THEORETICAL 



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, controUing 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 Leishmania: 

 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. 



Reference: Wright, J. H. (1902). 



WRIGHT'S STAIN 



For general differentiation of blood corpuscles; for 

 malaria parasites, trypanosomes, etc., in smears 



This stain is extensively used in America instead of Leishman 

 stain, which appears to be generally preferred by British workers. 



Best results are obtained with very thin films, and the distilled 

 water used should be buffered to pH 6-5-7-0. 



Technique: 



Fixation is unnecessary unless the films are to be kept for any 

 length of time before staining, in which case they should be fixed 



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