Building a Centrifuge to Diagnose Anemia for $30

This past fall, I made a news post that highlighted what could be done with $150 if you wanted to get some pictures from space, and the originating article did well to prove that where there’s a will, there’s a way. That old blurb of wisdom proves true all the time, as I’m often blown away by what someone has thought up, that I wouldn’t have ever thought possible. Today, there’s a new example of this.

Lila Kerr and Lauren Theis, two students at Houston’s Rice University, developed a centrifuge out of household items that could be used without electricity in order to separate blood in to diagnose an illness or disease. Most centrifuges used today are powered and require little manual input from the user, but in poor countries, or doing a power outage, using those may not be possible.

The solution? A salad spinner, some plastic lids, cut-up combs, yogurt containers and a hot-glue gun. Chances are, a lot of these items are already in your home. Bet you never thought you could spin blood with it!

According to the official press release, the salad spinner can rotate at 950 revolutions per minute, and that’s fast enough to separate blood into sections of heavier red blood cells and light plasma. Even better, it takes just 10 minutes, and you can do it with more than one test tube at a time. While spinning by hand requires concentration I’m sure, especially for 10 minutes, this sounds like a brilliant solution to a real problem.

The device will be put to the real-world test this summer, so hopefully we’ll hear about the experiences at that time.

They found that a salad spinner met those criteria. When tiny capillary tubes that contain about 15 microliters of blood are spun in the device for 10 minutes, the blood separates into heavier red blood cells and lighter plasma. The hematocrit, or ratio of red blood cells to the total volume, measured with a gauge held up to the tube, can tell clinicians if a patient is anemic. That detail is critical for diagnosing malnutrition, tuberculosis, HIV/AIDS and malaria.