1. Examination of faeces for parasites
Medical Parasitology
Examination of faeces for parasites

3. STOOL EXAMINATION Concentration techniques
Increase relative number of parasites for scanty infections.
Reduce background fecal debris.
Floatation
Sedimentation
Non Operculated eggs
Trematodes ( Schistosoma.)
Cestode
Nematode (Hookworms)
Cysts
Heavy eggs (Ascaris egg)
Operculated eggs (Trematodes)
Larvae (Strong stercolaris.)
Cysts

4. 2. Formol ether sedimentation
1. Saline sedimentation

5. 1. Saline sedimentation
Emulsify part of the faeces in distilled water or saline.
Strain through gauze.
Allow to sediment.
Decant the supernatant fluid.
Repeat washing and sedimentation until the supernatant becomes clear.
Microscopically examine the sediment for parasites.

6. Saline sedimentation Mesh wire gauze Saline Emulsify Conical flask
stool
Sediment

7. 2. Formol Ether sedimentation
Add 10 ml of 10% formalin to the previous sediment.
Mix and allow to stand for 10 minutes.
Add 3 ml of ether.
Centrifuge.
Four layers will form:
Ether at the top.
Plug of debris.
Formalin.
Sediment.
Decant the supernatant and microscopically examine the sediment.

8. Formol Ether Sedimentation
debris
10% Formalin
formalin
stool
Sediment
Thorough mixing
Conical flask centrif. tube
Ether adsorbs fecal debris & floats.
Formalin fixes & preserves the specimen.

9. 2. Zinc sulphate floatation 1. Saturated NaCl floatation

10. 1. Saturated NaCl floatation
Part of faeces is emulsified in saturated salt solution.
Strained in Erlenmyer flask.
The flask is completed to its top with salt solution without overflowing.
The flask is covered with a slide so as to contact the surface of the solution.
After 20 minutes the slide is turned over, covered and microscopically examined.

11. Slide is turned over, covered and microscopically examined.

12. 2. Zinc sulphate floatation
Part of stool is washed and sedimented by centrifuge.
The supernatant fluid is decanted and replaced by 33% ZnSO4.
Centrifuge.
The top fluid is microscopically examined.

13. Decant the supernatant
Centrifuge
Add ZnSO4