RVC/FAO guide to Veterinary Parasitology
Baermann technique: Procedure step 7

Use a Pasteur pipette to transfer a small droplet of the sedimented fluid from the petri dish to a microscope slide.

Add drop of iodine to fix the larvae and gently place a coverslip over the drop.

Any free-living nematodes will stain dark brown very quickly while the larvae of parasitic species will only stain very slowly as the larval sheath protects the body.

slide with drop of sedimented fluid and separate coverslip

slide with drop of fluid with iodine being added

slide with drop of sedimented fluid and iodine with coverslip separate

coverslip being put in place

prepared sample on slide with coverslip in place