A new nanotechnology-based technique could lead to a test for diagnosing the early signs of Alzheimer's disease.
The Bio-Barcode-Assay can recognise ADDL, a protein that accumulates in the brains of sufferers.
It is a million times more sensitive than conventional tests and could revolutionise disease detection.
In future, it might form the basis not only of a test for Alzheimer's but also for types of cancer, the human form of mad cow disease and HIV.
Details of the technique have been outlined at a one-day conference in London.
Until now, doctors had no way of diagnosing Alzheimer's disease in their patients. The disease could only be confirmed after death, by studying brain tissue.