A biological system that helps people with diabetes monitor their glucose levels has been developed by scientists.
The biological system developed by the Missouri University of Science and Technology students uses segments of DNA embedded in bacteria to detect glucose.
They believe their development could lead to a new type of test strip for diabetics.
"We designed DNA so that bacteria that have DNA would sense a change in osmolarity due to the presence of glucose," said Erica Shannon of Wildwood, Mo., a senior in biological sciences at Missouri S and T and president of the campus's iGEM chapter- the International Genetically Engineered Machine Foundation.
Osmolarity refers to the concentration of a compound - in this case, glucose - in a solution.
For their project, the students designed genes that allow the bacteria - a non-virulent strain of E. coli - to sense the presence of the simple sugar glucose. The bacteria emit a yellow glow when glucose is present. As glucose concentrations become higher, the glow becomes brighter.
It would require replacing the fluorescent gene with one that would cause the bacteria to change colour based on glucose levels. This in turn could lead to the development of diabetes blood test strips that could indicate glucose levels based on various colours.
For example, a test strip might turn green if glucose levels are within normal ranges, yellow if borderline and red if elevated.
"All you would have to do is put the DNA inside a bacteria and you've got your test strip," says Shannon.