Flotation process
The flotation method is a coproscopic detection method (fecal examination) for the detection of parasitic developmental stages such as eggs, oocysts , cysts or larvae . It is used in both human and veterinary medicine.
Principle of the procedure
Eggs with a low density float on the surface in solutions with a higher specific gravity .
The procedure is suitable for the detection of:
- Cyclophyllidea (an order of the real tapeworms )
- Eggs of roundworms
- Coccidial oocysts
- Giardia cysts
Examples of flotation solutions
Only solutions with a high specific weight, i.e. a high density, are suitable for the flotation process. Usually these are saturated salt or sugar solutions.
- saturated saline solution (400 g NaCl in 1 l H 2 O)
- saturated zinc sulfate solution (704 g ZnSO 4 in 1 l H 2 O)
- Sugar solution (500 g sucrose in 320 ml H 2 O)
execution
Fecal sample and flotation solution are mixed together. The resulting suspension is poured through a sieve with a mesh size of 250 to 300 μm and a funnel into a centrifuge tube. Either you centrifuge the tube for five minutes at 2800 / min or let the whole thing stand for 15 to 20 minutes. The superficial layer is then removed with an eyelet and applied to a slide. Alternatively, ordinary tubes or plastic containers can be used, on which a cover slip is placed, which is carefully removed after 15 to 20 minutes and placed on a slide. This is examined under the microscope with a small magnification.
Web links
- Information from the FLI on commercial investigation kits ( Memento from November 22, 2009 in the Internet Archive )
- Pictures of the flotation process