Luminous cells from jellyfish can be used to diagnose cancers deep inside the body, scientists have said.
The process uses the green fluorescent protein (GFP) enabling jellyfish to glow in the dark.
Researchers in North Yorkshire found it can be targeted at cancer cells allowing them to be spotted using a special camera.
A team from the Yorkshire Cancer Research Laboratory at York University has developed the procedure.
The team's leader, Professor Norman Maitland, believes it will revolutionise the way some cancers are diagnosed.
He said: "Cancers deep within the body are difficult to spot at an early stage, and early diagnosis is critical for the successful treatment of any form of cancer.
"What we have developed is a process which involves inserting proteins derived from luminous jellyfish cells into human cancer cells.
"Then, when we illuminate the tissue, a special camera detects these proteins as they light up, indicating where the tumours are."
The process is an extension of the work done by American chemist Dr Roger Y Tsien, who won a Nobel Prize in 2008 for taking luminous cells from the crystal jelly species of jellyfish and isolating the GFP.
Prof Maitland said: "When we heard about Dr Tsien's work, we realised how that advance might be useful in the diagnosis of cancer.
"X-rays, for example, struggle to penetrate well deeply into tissues and bone, so diagnosing dangerous microscopic bone cancer is difficult.
"Our process should allow earlier diagnosis to take place."
The York team's process uses an altered form of the protein so that it shows up as red or blue, rather than its original green.
Viruses containing the proteins are targeted to home in on tiny bundles of cancer cells scattered throughout the body which are too small to be seen by conventional scanning techniques.
But the viruses grow and, while doing so, make more and more of the fluorescent proteins.
"When a specially-developed camera is switched on, the proteins just flare up and you can see where the cancer cells are." said Prof Maitland.
"We call the process 'Virimaging'."
Deep in body
The team expects the procedure to be ready for clinical trials within five years, if the research continues to go to plan.
Prof Maitland said one problem, however, may be the availability of the specialised cameras needed for the process.
A United States company is the only one which has so far designed and built a camera system which allows the jellyfish proteins to be seen with the desired resolution so deep in the body.
This kit costs about £500,000 and Prof Maitland said he was currently raising the funds to buy one.