Harvard University chemists have built a centrifuge with some plastic tubing, tape, and an egg beater.

It can separate plasma from blood cells, and could help doctors in remote villages perform simple lab tests.

The researchers described their invention in the current issue of Lab on a Chip , which has published useful hacks in the past. Last year, the same journal explained how to make microfluidic devices from Shrinky Dinks.

"Our advisor, Professor George Whitesides, has always been interested in unorthodox use of ordinary items," said Sergey Shevkoplyas, a co-author of the centrifuge paper.

The lead author of that report, Amy Wong, recently graduated and is now working for the X-Prize foundation, running a contest that will encourage scientists to develop a better test for tuberculosis.