Worth more than gold

Worth more than gold

Cawthron Institute made the front page of our local paper tonight with a great story about a new business they have developed. Cawthron has become an important source for rare marine toxins, used as standards for calibrating the instruments used for detecting them in food such as shellfish. They get very high prices for these chemicals: one example was quoted where €3000 was paid for 1 mg (that’s one thousandth of a gram). There were many interesting stories along the way. Here’s one of them:

The business has its beginnings more than 12 years ago, when people were searching for better ways of testing shellfish for these toxins. With the help of people in Japan (esp. Prof Takeshi Yasumoto, from Tohoku University) and Canada (Dr Mike Quilliam, from the NRC Institute for Marine Biosciences), Pat Holland and Paul McNabb from Cawthron managed to develop routine analytical methods which were quicker and more accurate. After a long hard battle, they were eventually accepted by New Zealand authorities. Some years later, regulators in North America and Europe began to adopt them too, creating a market for these very expensive toxin standards.  (Their adoption has also spared hundreds of thousands of mice from an unpleasant death in the “mouse bioassay”, but that’s a different topic.)

Around 2003, give or take a year, we got news of an algae bloom off the West Coast of the South Island. We asked for a seawater sample. Using our new LC-MS, we looked for some toxins. “Yep, there’s heaps there” said analyst Paul McNabb. “There must be 5 or 10 picagrams of pectenotoxin (PTX) in that little sample”. (It takes 1 million picagrams to make 1 microgram and 1 million micrograms to make 1 gram)

Lincoln Mackenzie, who had well developed antennae for such things, immediately charged off to Greymouth in a hired van, armed with a portable microscope, samplers, pumps, masses of flexible hose and as many 20 litre plastic carboys as he could get hold of. He rented a commercial fishing boat in Greymouth and set off to find the bloom. This meant collecting seawater samples from various depths and studying them under the microscope – his quarry was so small that it was invisible to the naked eye. Eventually he found it, a massive bloom in a fairly narrow band, 4-5 metres down below the sea surface. He started pumping, using fine plankton nets to concentrate the algae bloom into something resembling Coca-Cola. After 12 or 15 hours, he had filled all the carboys and headed home.

Weeks later, when the contents had been analysed, we realised that we had the world’s supply of PTX for the next 4-5 years in Lincoln’s bottles. We just had to purify it, analyse it very accurately and present it in a form that could be used as a standard.

You can see that was a long, difficult job which is now paying off.  Commercialisation of research sometimes takes a long time.

Here’s the label from a box of ampoules with the very first of these standards produced around 2004, a label that I was very proud of:

PTX label


NZ Herald coverage


Cawthron Institute





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