Illuminating Antibody test

Whether fighting the coronavirus or some other pathogen, the body’s immune system produces small proteins called antibodies that recognise and bind to the invader. Rapid tests for the presence of antibodies in a person’s blood tend to be binary – yes or no, the antibodies are there or not. To get quantitative information, which can be helpful for knowing whether an infection is ongoing, the extent of someone’s immunity, and so on, more extensive laboratory tests are required. A newly developed antibody test (pictured), however, is both fast and quantitative. It’s comprised of cotton threads (the star patterns) loaded with bioluminescent molecules that change colour from green to blue when antibodies bind them. A drop of blood is placed on a star and the more antibodies present, the bluer the hue becomes. What’s more, to capture the results, all that’s needed is a smart phone camera with a lens adaptor.

Written by Ruth Williams

Ruth Williams

Writer

Ruth is a freelance science journalist based in the US. She's a regular correspondent for The Scientist, and her work has appeared in The Lancet, Nature, Scientific American Mind, BBC Focus and elsewhere. Twitter @rooph

Website

• Image adapted from work by Kosuke Tomimuro and colleagues
• Department of Applied Chemistry, Keio University, Yokohama, Japan
• Image copyright held by the original authors
• Published in ACS Sensors, May 2020