VPA 211: General Veterinary Parasitology and Helminthology (3+1)

Sedimentation technique

SEDIMENTATION TECHNIQUE (Centrifugal sedimentation technique)

• A small quantity of about 2 g from different areas of the sample of the faeces is taken in a cup.
• Add water about 3/4^th of the centrifuge tube in to the faecal material.
• Thoroughly emulsify the faecal material.
• This emulsion is then strained through a sieve (tea strainer) to remove all the coarser particles.
• The filtrate which should contain the eggs is then poured into a centrifuge tube just up to a half inch below the brim
• Centrifuge at 2,000 r.p.m for 2 minutes.
• All the eggs get packed at the bottom of the tube along with the sediment.
• The supernatant fluid is then poured off.
• A drop of the sediment is placed on the slide, covered with a thin coverslip. (It is always better a thin faecal smear is the best for examination)
• Examine under low power (10 x) of microscope for the presence of egg/larval stages.

Advantages

• This method is the most reliable one by which one can recover the eggs of three types of worms viz.,Trematode, Cestode and Nematode.

Disadvantages

• Presence of too many faecal materials and fibers may hinder the visualization of egg.

Note: 0.5% glycerine in water can be used for emulsifying the faeces instead of plain water.