WATCHING a protozoan version of synchronised swimming could provide a low-cost way of detecting toxins in water.
Many species of protozoa are covered in hair-like cilia that beat in a coordinated way to propel them through a fluid. Chemicals in the fluid can interfere with the transport of calcium to the cilia, with different chemicals altering the microbes鈥� swimming style in different ways, says Robert Curtis at Petrel Biosensors, a spin-out of the in Massachusetts.
Curtis鈥檚 team placed protozoans in test solutions containing different common toxins, and used a camera to assess the resulting swimming patterns. Using these as reference points, the team is now developing a device that uses algorithms to match the microbes鈥� swimming style in a water sample to the toxin present, if any. 鈥淵ou can see very distinct patterns of swimming, so we can say if it鈥檚 a heavy metal toxin or a phospho-organic toxin,鈥� Curtis says.
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The company says the instrument will cost around $15,000. Each test will cost $1 to $2 and take around 30 seconds, unlike tests with existing devices, which can cost up to $400 and take two to three days, says Curtis.
