and Laboratory Methods. 2467 



A Review of the Methods of Staining Blood. 

 XI — Concluded. 



10. For Staining Malarial Parasites. 



Celli and Guarnieri (1889) stained the living parasites in a solution of methy- 

 len blue in serous fluid. Ascitic fluid is collected with aseptic precautions in 

 sterile test tubes. To these a sufficient quantity of methylen blue is added, 

 which, after floating for a short time, sinks slowly to the bottom, coloring the 

 fluid a deep blue. After filtering into another test tube the solution remains 

 good for a long time. The finger of the patient is cleansed and punctured with 

 a needle, and with a glass rod a drop of the staining fluid is placed upon the 

 drop of blood that appears. From this mixture a drop is transferred to a cover- 

 glass and allowed to spread out on a glass slide, a little pressure being used to 

 spread out the red corpuscles and prevent the formation of rolls. The staining 

 requires some time, and best results are obtained by leaving the preparation 1 

 to 2 hours in a moist chamber. The preparations are not wholly permanent. 



Feletti (1S90) stained the living parasites by the following method : A small 

 drop of an alcoholic solution of methylen blue — -1 part to 5 — is placed upon a 

 slide and allowed to dry by passing the glass over a flame. A drop of blood 

 collected upon a cover-glass is placed upon the stained area and the cover-glass 

 surrounded with paraffin. The methylen blue is redissolved in the blood serum 

 and stains the parasites. 



Mannabcrg (1893) describes the following method of staining malarial blood 

 with haematoxylin : The dry preparation is first floated for 5 minutes upon dis- 

 tilled water, then dried between blotting paper, then drawn several times through 

 a very dilute solution of acetic acid (1 drop of acetic acid to 20 c. c. of distilled 

 water) until it has completely given up its hemoglobin. The almost completely 

 colorless preparation is then placed for 2 hours upon a fixing solution of picric 

 and acetic acid (II, B, 2, 1), from which it is put into absolute alcohol for another 

 two hours. Thereafter follows the staining for from 12 to 24 hours in alum 

 haematoxylin (III, A, 3, a). Lastly clear up the preparation by means of acid 

 alcohol (75 per cent, alcohol with 0.25 per cent, hydrochloric acid) and ammo- 

 nia alcohol (3 drops of ammonia to 10 c. c. of 75 per cent, alcohol), wash in 80 

 per cent, alcohol and mount in xylo-Canada balsam. The preparation is first 

 washed in water and acetic acid to remove the albuminous substance, which is 

 apt to cause troublesome precipitates in the subsequent treatment with picric 

 acid. Parasites and leucocytes stain blue, the red corpuscles remain colorless. 



J/a/^r/w7f'i-/^r (1891) recommends Sahl's borax methylen blue (III, A, 4, c) 

 after several minutes' fixation in absolute alcohol. 



Marchoux (1897) recommends thionin (III, A, 9, a) for staining malarial 

 blood. 



Schuffiicr dries the preparations 6 to 30 hours in a place somewhat shielded 

 from light, fixes in 5 per cent, glycerin and formalin 5 to 10 minutes, washes 

 and stains in hcematoxylin 1 to 10 minutes, according to strength. 



