40 STAINING METHODS 



Wash in water five minutes, then stain with Giemsa's stain as used in 

 blood work for one to ten hours. Wash and mount. 



Vital Staining of Protozoa with Neutral Red Solution. As a stock 

 solution one uses a 0.5% aqueous solution of neutral red. 



The drop of salt solution or water on the slide should be tinged a 

 light violet-rose color with a fraction of a loopful and the faeces or other 

 material emulsified in this. 



Protozoa take a rose-pink color with a distinct differentiation be- 

 tween endoplasm and ectoplasm. 



Should the faeces be quite alkaline the neutral red will be decomposed 

 with the formation of bilirubin-like crystals. 



The Giemsa formalin method described under Blood Work is of 

 value in certain cases. 



Highly to be recommended for the staining of protozoa, whether in smears or in 

 sections, is the Panoptic method. 



1. Wright's or Leishman's stain for one minute. 



2. Dilute with water and allow dilute stain to act for three to ten minutes. 

 Wash in water and then 



3. Pour on dilute Giemsa's stain. Allow to stain from thirty minutes to twenty- 

 four hours. Differentiate with i : 1000 acetic acid solution until blue stain just 

 shows commencing diffusion into the acetic acid. Then wash in water, 95% 

 alcohol, absolute alcohol and treat with xylol and mount in liquid petrolatum. 



With preparations other than blood smears, as sections, it is better to go from 

 95% alcohol to oil of origanum, then mount. 



Owing to the great value of a sharp nuclear picture in differentiating amoebae 

 it is of great importance to use some iron haematoxylin method. That of Weigert 

 is given in the appendix. 



Fix moist smears, film surface down, in Zenker's fluid for five to ten minutes. 

 Wash in water, treat with Gram's solution and wash with 70% alcohol until all the 

 yellow color is discharged. Wash in water. Then stain with Mallory's phospho- 

 tungstic hamatoxylin for one-half hour. Wash clear and mount. See appendix. 



Mallory's Differential Stain for Amoebae. Staining in saturated aqueous 

 solution thionin for from three to five minutes. Next differentiate in 2% aqueous 

 solution oxalic acid for one-half to one minute. Then wash in water, clear and mount. 

 Nuclei of amoebae are stained a brownish red. 



