Washington, Aug. 10 (Reuters): US researchers today said they had come up with a system for turning mice into custom-made, high-output antibody factories.

They hope their system will lead to faster and more efficient ways to identify proteins, which in turn are used to design new drugs, in tests for various diseases, in genetic sequencing and in basic genetic research.

Antibodies are immune system proteins that specifically recognise and attach to proteins, called antigens. They evolved to help the body recognise and fight invaders such as bacteria and viruses, or to find and destroy mutant cells including cancer cells.

Scientists use them as tools. For instance, many tests that check to see if a patient has a disease use antibodies. And in basic lab work, antibodies can be engineered to identify proteins for various uses. “Antibodies are the most commonly used reagents to measure proteins in humans, but antibodies, up to now, have been very complicated and expensive to create,” said Ross Chambers, assistant professor of internal medicine at the University of Texas Southwestern’s Center for Biomedical Inventions, who worked on the study.

Writing in the September issue of Nature Biotechnology Chambers, the institute’s director, Stephen Albert Johnston, said they found a quick way to force lab mice to create antibodies against any protein they wanted, by making a kind of vaccine.

In 1992, Johnston’s team invented genetic immunisation, which allowed scientists to inject genes instead of proteins into animals to produce an immune response to a particular protein.

The new technique, a modification of genetic immunisation, uses the antigen gene they want to target — the DNA coding for the protein they are after. They added several elements to make the method far more efficient.