The egg-beater 'centrifuge'

Royal Society of Chemistry

Scientists have shown how an egg beater can be made into a hand-held centrifuge to separate plasma from whole blood for testing in resource-poor settings.

The researchers, from The Whitesides Research Group at the US-based Harvard University, published their work in the journal Lab on a Chip this month (14 October).

The team attached plastic tubing to the manual egg beater, which when rotated separates the plasma from the blood cells, acting as an alternative to expensive electrically-powered centrifuges.

"The lack of centrifuges is one of the main reasons why many diseases go undiagnosed in developing nations," Malancha Gupta, a postdoctoral fellow at the group and an author of the paper, told SciDev.Net.

"To the best of our knowledge, there are no practical alternatives to centrifugation for separating plasma from whole blood, and the absence of this basic medical technology in the hands of health workers prevents them from performing diagnostic assays and, therefore, limits the availability of healthcare severely."

The plasma produced in this manner was used effectively in a cholesterol diagnostic test, and can, in principle, be used in any diagnostic test using plasma, including those for infectious diseases like hepatitis B and cysticercosis, a parasitic disease of the nervous system.

Unlike its conventional counterpart, using the hand-powered 'centrifuge' requires little training. It can be easily assembled from cheap and locally-available parts, and the materials used are light and robust enough to travel easily.

"The healthcare infrastructure in which the egg beater centrifuge would be most useful is an environment where there are no clinics or hospitals to diagnose patients, and no electricity or electrically-operated equipment."

"The egg beater we used in our study is sold widely in India for 105 rupees (US$2.11), and can therefore be purchased locally by healthcare workers," says Gupta.

The research group hopes that this piece of equipment, combined with cheap paper-based diagnostic devices also developed by the group, can be used to facilitate faster treatment of diseases by providing on-the-spot diagnostic tests in the field.

Link to full paper in Lab on a Chip