Baermann Funnel Introduction to a “Baermann funnel”
A device used to extract nematodes (Nematoda) from a soil sample or plant material. A muslin bag containing the sample is submerged in water in a funnel sealed at the lower end by a rubber tube and clip. Being heavier than water, the nematodes pass through the muslin and sink to the bottom. After about 12 hours they can be collected by drawing off the bottom b ottom centimetre of water. The efficiency of the device devi ce is increased by gentle warming which immobilizes the nematodes. Below is an article on a use of Baermann funnel, for further reading. (‘Strongyloidiasis” is a human parasitic disease caused by the nematode (roundworm) Strongyloides stercoralis. stercoralis. )
BAERMANN FUNNEL TECHNIQUE FOR NEMATODE LARVAE
PRINCIPLE The Baermann funnel technique for detection of nematode larvae reli es on the phenomenon of the migration of the larvae downward from soil or feces to water of warmer temperature. After permitting sufficient time to permit migration, the warm water is drained off, centrifuged, and examined microscopically for the presence of the larvae. The use of a Baemann apparatus is especially efficient for attempting to detect Strongyloi des larvae in stool specimens.
CLINICAL SIGNIFICANCE The presence of nematode larvae in human feces indicates infection with the parasites. Strongyloides infections may be latent and go undetected for many years; auto-infection is a risk. The detection of strongyloidiasis has become increasingly important in patients who have immune deficiencies. (Sourced : United States Department Of State website)
Determination of types of aquatic organisms Objective: To determine the types of aquatic or semi-aquatic organisms by using Baerman funnel. Apparatus: Baermann funnel, retort stand, 100cm3 beaker, magnifying glass, microscope, glass slide, cover slip, forceps, glass rod. ro d. Materials: 4% formalin solution, soil sample Procedure.
1. An appreciable amount of soil sample was placed inside a muslin bag and was tied up using a piece of thread. 2. The bag was then suspended with the help of a glass rod in the middle of the Baerman funnel which was clamped on a retort stand and left aside for 24 hours. The bulb was lit up. 3. A small beaker (100 cm3) containing 4% formalin solution was placed under the Baerman funnel. 4. Periodically, the clip was loosened to allow the aquatic organisms collected at the base of the Baerman funnel to drain into the beaker sample. 5. The organisms in the formalin solution were examined under a microscope. They were then identified and were then drawn.
Discussion:
This technique was based on the fact that aquatic soil organisms such as Amoeba sp., Paramecium sp. and euglena sp. are denser than water. The higher temperature and light intensity in the upper layer causes these organisms to gather at the stem of the funnel. When the organisms fall into the formalin solution, it will act as a preservative to preserve the organisms. Methods to improve accuracy of results obtained:
1. Ensure that the lamp is not placed too close to the funnel as extreme temperatures may kill the organisms. 2. The experiment is carried out for a few days to ensure that all the organisms are removed from the soil sample. Conclusion:
From this experiment, soil organisms such as Amoeba sp., Paramecium sp. and Euglena sp. are found in the soil sample. This proves that the soil sample is a suitable habitat for aquatic soil organisms.
