Baermann technique
Purpose
- For separation of helminth larvae from cultured fecal material
 
Principle
The Baermann technique is based on the active migration or movement of larvae.- Feces are suspended in water.
 - The larvae move into the water.
 - They sink to the bottom and can be collected for identification.
 
Procedure
- Take a funnel and fit a short piece of tubing to the stem.
 - Close the tubing with a clamp or spring clip.
 - Support the funnel on a single stand.
 - Double layer of cheesecloth
 - Add 5-10 grams of fecal material
 - Put this material the funnel in the suspended form (cloth should not touch the funnel)
 - Fill the funnel with lukewarm water.
 - Make sure the fecal material is covered.
 - Leave the apparatus to stand for 24 hours.
 
Larval recovery
- Draw off a few mL of fluid from the stem of the funnel into a test tube.
 - Leave for sediment for at least 30 minutes.
 - or centrifuge at 1000 rpm for 2 minutes.
 - Take a small droplet of the sediment to a microscope slide.
 - Add a drop of iodine to fix the larvae and gently place a coverslip over the drop.
 - Free-living nematodes will stain dark brown very quickly
 - Parasitic spp. Light stain due to protective sheath
 
Pseudoparasites/Pitfalls
- Wide variety of objects that resembles parasites/larvae are termed as Pseudo Parasites/Pitfalls
 - They leads to mis-identification
 - With experience, these can be covered
 
- Inorganic materials
 - Oil droplets
 - Yeasts
 - Fungi
 - Plant material
 - Plant grains, fibers, straws
 - Larval or adult insects
 - Cellular elements
 




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