National Measurement Institute: DNA reference materials in water testing
The National Measurement Institute (NMI) collaborated with researchers from the University of NSW and Diagnostic Technology, an Australian company, to develop a commercially available genetic test kit for algal toxins in water. Phytoxigene™ CyanoDTec is a molecular (DNA) based technology that detects and discriminates the presence of toxin from non-toxin producing Cyanobacteria (Blue Green Algae) in freshwater.
What is an algal bloom?
An algal bloom is a rapid increase in the population of algae in an aquatic system. Algal blooms composed of Blue Green Algae, some of which are known to naturally produce biotoxins, are called Harmful Algal Blooms (HABs). Harmful algal blooms can produce extremely dangerous toxins that can cause people and animals to become very sick. Predicting these HAB events and knowing if they contain toxin producing species is critical in the management of the event.
HAB events occur in many parts of the world, including Australia, North America and South Africa and can reoccur at frequent intervals. The impact of such events can be very substantial, such as in the case of a HAB event in North America’s Lake Erie in 2014 which resulted in the issuing of a “Do Not Drink” advisory to residents of the city of Toledo.
How does the test kit work?
Under contract from Diagnostic Technology, NMI designed, produced and characterised DNA reference materials using droplet digital polymerase chain reaction technology. The material consists of plasmid DNA-carrying defined copy numbers of cyanobacterial toxin genes target sequences. The material is used to produce standard solutions for the CyanoDTec kit. It allows users to be confident of their measurements and to ensure these measurements are comparable between laboratories and over time.
The kit can be used as an early screening tool to prompt further testing for toxins via other methods. The test can be completed within 2-3 hours (including time taken to extract a water sample) and is cost effective. Use of this technology has the potential to make earlier detection of HABs possible which will enable a more rapid response to any outbreak.