Animal Parasites 387 



2. Centrifuge 45 seconds, 2500 rpm. Break up any plug at top and 

 decant supernatant fluid. 



3. Add 2-3 ml. of normal saline and shake to resuspend the sediment. 

 Fill tube with normal saline to within 1 cm. of top and centrifuge. 



4. Decant supernatant fluid. Take a small quantity of the original 

 fecal specimen on the end of an applicator stick and mix well with 

 sediment at bottom of tube. 



5. With an applicator stick, transfer as much as possible of the ma- 

 terial to a clean slide. Smear as for a conventionally made slide and 

 fix immediately in Schaudinn's. 



6. Stain as usual, hematoxylin, Lawless' method, etc. 



Goldman (1949) Smears 



fixation: Schaudinn's (page 21), 40°C: 5-15 minutes. 



solutions: 



Stock solution A: 



hematoxylin, 10% in 95% alcohol (10 gm./ 



100 ml. 95% alcohol) 1.0 ml. 



95% ethyl alcohol 99.0 ml. 



Stock solution B: 



ferric ammonium sulfate 4.0 gm. 



glacial acetic acid 1.0 ml. 



sulfuric acid, concentrated 0.12 ml. 



distilled water 100.0 ml. 



Working solution: 



Equal parts of A and B. It turns purple, but within a few hours 

 changes to dark brown. Then it should be filtered and is ready for 

 use. If it ttirns greenish black, it is unsuitable for staining; the he- 

 matoxylin was too ripe and became overoxidized. 



Hanson's Iron Trioxyhematein (page 127) may be used in same way. 



procedure: 



1. Rinse slides in 70% alcohol and treat with iodized alcohol. 



2. Wash in several changes of 50% alcohol until brown color re- 

 moved. 



3. Stain in hematoxylin progressively : 3-5 minutes. 



4. Wash in running water: 15-30 minutes. 



5. Dehydrate, clear, and mount. 



results: 



protozoa — black nuclear stain 



