Cryptosporidium鈥攁 waterborne parasite that causes diarrhoea
and vomiting鈥攃an be detected in less than three hours with a system
developed at British water company, Thames Water. Other tests can take days.
A fluorescently labelled antibody first sticks to the surface of any
Cryptosporidium oocyst. The sample is filtered onto a membrane and scanned
with a laser-based instrument called ChemScan, made by the French company
Chemunex. This recognises any particles that fluoresce at the correct
wavelengths and are the right size to be Cryptosporidium oocysts.