INTRODUCTION
The faecal flotation test is used to determine the presence of roundworm eggs in faeces.

Commercial variations on this test such as Ovassay are available and work upon a very similar principle.

EQUIPMENT

• Protective gloves, apron and mask.
• Fresh faecal sample.
• Wide mouthed screw-top glass jar.
• Saturated salt solution.
• Glass beads (for mixing).
• Sieve.
• Pipette.
• Test tube & test tube holder.
• Cover slip.
• Microscope slides.
• Pencil for labelling slides.
• Microscope.

METHOD

1. Put on protective apron, gloves and mask; ensure that long hair is tied back and any jewellery removed.
2. Place 2g of faeces in the screw-top glass jar.
3. Add 30mls of saturated salt solution.
4. Add glass beads, replace cap and agitate vigorously in order to break up the sample.
5. Sieve the mixture.
6. Fill the test tube with solution until a convex meniscus is formed.
7. Place a cover slip over the test tube and leave for 15 minutes.
8. Carefully lift off the cover slip and place it onto a labelled microscope slide.
9. Check the microscope is safe to use - examine the plug and power cable for damage, then switch on.
10. Examine the slide under low power to observe the field for eggs.

NB. As with the McMaster technique, this method is unsuitable for confirming the presence of tapeworm eggs, since they sink in the saturated salt solution. Tapeworm infestation is usually diagnosed by the visualisation of gravid segments in faeces.