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 centimetre of water. The efficiency of the device is increased by gentle warming which immobilizes the nematodes.

Baermann funnel A device used to extract nematodes 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 centimetre of water. The efficiency of the device is increased by gentle warming which immobilizes the nematodes.