Specimen: sample containing Schistosomal eggs
The hatching test consists of:
(1) Placing the sample in warm distilled water at (around 48.9°C or 120°F).
(2) Expose the sample to a bright light.
(3) Examine the specimen periodically, looking for miracidia within the eggs.
In viable eggs miracidia will eventually escape from the eggs and start swimming around in the water.
Causes of a false negative test:
(1) placing the sample in fixative
(2) using water that is too cold or too hot
(3) placing the sample too close to the bright light, with overheating of the specimen
(4) viewing the specimen too infrequently to observe the miracidium escape
(5) letting the sample dry out