- Add 1 ml of freshly drawn blood to 9 ml of 2% formalin (aqueous) in a centrifuge tube.
- Mix well to lyse red blood cells.
- Centrifuge for 5 minutes at 1500 rpm.
- Pour off the supernatant fluid. Note: Invert the tube completely when decanting the supernatant.
- Add a drop of 1% aqueous methylene blue. Adjust the amount to suit yourself, it stains the microfilariae blue and makes them easier to view). Then stir or mix up the sediment in the bottom of the tube.
- Place a drop of the stained mixture on a microscope slide and add a cover slip. Examine under a microscope.
Modified Knott Method
