They are used to probing human tissue samples for tiny traces of disease, but a team of Kiwi scientists couldn't have prepared for one of their oddest challenges yet - helping restore a celebrated artist's forgotten painting.
At Auckland Art Gallery this weekend, Frances Hodgkins' painting Still Life: Anemones and Hyacinths will go on display for the first time in nearly 60 years, thanks to a conservator's painstaking restoration and some cutting-edge analysis by Auckland University scientists.
The piece, thought to have been painted by the influential New Zealand artist in about 1925, had been kept in storage at the gallery since 1956.
Although it had been in good repair when it entered its collection, the upper layer of brown paint around the flowers was flaking severely and no suitable treatment was available.
Fifty-nine years later, conservator Genevieve Silvester developed a remedy and restored the work to a condition where it can now be shown in public.
"The most critical part of the treatment was to stabilise the flaking paint to prevent any further loss," she said.
To find out the best type of adhesive to use, a pair of tiny samples of the brown paint were taken to Auckland Science Analytical Services at Auckland University.
There, technician Martin Middleditch analysed the extracts using a new Sciex TripleTOF mass spectrometer, the most sensitive equipment available in New Zealand for identifying tiny amounts of different proteins in highly complex materials.
While Mr Middleditch and his colleagues are more used to analysing tissue samples, typically for traces of rare diseases like amyloidosis, the results this time showed the paint contained bovine proteins derived from cow's milk, commonly known as casein.
"It was out of my comfort zone on this one," he said with a laugh.
"We are used to doing soft pieces of tissue, but now we've had this hard, crispy piece of 100-year-old painting."
After this discovery, Ms Silvester found a suitable adhesive to the cracks of the flaking paint.
In a process that took more than 100 hours, she used a heated spatula to warm each tiny flake to increase its flexibility before gently pressing it back into place.
The gallery's principal conservator, Sarah Hillary, said the treatment was "very challenging, but a remarkable success, and the artwork can finally be shown again to the public".
It will be shown as part of the exhibition Frances Hodgkins: Forgotten Still Life, opening this Saturday, which explores the high degree of experimentation Hodgkins brought to the subject of still life and includes work in other media, including pencil, watercolour, gouache and oil.
• Widely considered one of New Zealand's most prestigious and influential painters, and arguably the country's most significant expatriate modernist painter of the 20th century.
• Born in Dunedin in 1869 and died in Dorset, England, in 1947, aged 78. At the time she was regarded as one of Britain's leading artists.
• Painted in watercolour and later changed to oil, and her many achievements included being invited to display her work at the Venice Biennale exhibition in 1939.