Saponin Lysis Concentration for Filariae

The saponin lysis method can be performed on either EDT A- or citrate-anticoagulated blood. Saponin solution to lyse erythrocytes is available in most laboratories for use with automated hematology instruments. 

Mix the packed erythrocytes with 50 ml of 0.5% saponin solution in 0.85% saline. 

Decant and discard the supernatant (there should be about 1 ml of sediment). 

Spread several drops of sediment on a glass slide (1 by 3 in.), and examine two such uncovered wet mounts for motile microfilariae. Allow the wet mounts to dry before they are fixed and stained. 

Prepare four or five similar wet mounts and examine them as described above. To. each slide, immediately add 2 drops of 1% acetic acid solution and mix it well (microfilariae will be killed and straightened). Allow the slide to air dry. 

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