The challenge is to find out what all those genes do and their contribution to health and disease

Dr James Sharpe

But the developers, from the Medical Research Council Human Genetics Unit in Edinburgh hope it will eventually be used to improve medical diagnosis using tissue biopsies from patients.

OPT allows unprecedented insights into the structure of tissues.

The method could help scientists track the tissues of a developing embryo, or map gene expression in organ systems.

It works by imaging the entire object from many different angles.

A computer then reconstructs the object by accumulating all the information and calculating a 3D image.

Previously, three dimensional tissue images had to be built up laboriously, by compiling hundreds of images from thin sections.

The technique also has the advantage of being able to examine tissue up to 15mm across, in contrast to a maximum of one millimetre using previous optical imaging technologies.

Huge potential

Developer Dr James Sharpe said: "The genome sequencing projects have successfully identified many thousands of genes, but now the challenge is to find out what all those genes do and their contribution to health and disease.

"There's a tremendous amount of research worldwide into how genes work and the first step in understanding the function of a new gene is often to discover exactly where it's active.

"Understanding this function in mice can help us look at similar gene function in humans."

Dr Sharpe said OPT was efficient and cost effective.

Thus it should be feasible to use the technology to generate comprehensive information for all genes of the genome.

This would provide scientists with a 3D map of where the genes perform their function.

He said: "This would be an invaluable resource for scientists around the world, comparable to the map of the genome itself."

Scientists are already working on a comprehensive 3D atlas of mouse genes.

Most mouse genes function in the same way as their human counterparts.

The research is published in the journal Science.