Scientists have developed a tiny microscope - the width of a human hair - which they say could "revolutionise" the examination of biological samples.
The biochip has been funded with a £2.2m grant
Cardiff University researchers said the optical biochip could help doctors test for diseases and develop new drugs.
The team is looking to integrate the biochip into medical technology, such as diagnostic equipment.
The biochip, developed with a £2.2m grant, works by emitting tiny lasers which analyse a cell.
Biological samples can be placed on the biochip - just visible to the human eye - which then relays what it finds via an electrical signal.
In theory, the biochip could detect diseases such as HIV, malaria and some cancers, or aid drug development by analysing how a cell reacts to a substance.
Cell diagnosis is currently done by traditional microscope or by hospital-based equipment.
Lead researcher Professor Paul Smith said: "Our research could help revolutionise how we examine biological samples.
"Our next step will be to develop simple, small diagnostic devices.
"Future generations may be able to use these as the basis for hand-held system that will be able to perform diagnostic functions in the field that currently require a laboratory test."
Professor Smith said future technology breakthroughs might enable the chip to be embedded in the body.
The challenge now, he said, was to develop something useable from the prototype, but more funding was needed.
Professor Julia Goodfellow, chief executive of the Biotechnology and Biological Science Research Council, which has helped to fund the project, said the biochips had the potential to make a "real difference" in medicine.
But Trudie Lobban, of the Medical Technology Group, a campaign group for patients, industry and health professionals, warned the benefits of the development might not be realised.
"The NHS is slow at getting new technologies into the system, the same could happen with this.
"But it certainly sounds like a welcome development, anything that helps improve the treatment of patients is obviously good."