Ordinarily, red blood cells should look like a disc with a medium-sized dimple on the top and bottom. If that dimple is either too large or too small, it can indicate the presence of a disease such as sickle cell anemia or malaria. Pathologists traditionally have had to examine blood samples under a microscope, manually looking for these misshapen cells. A new technique developed at the University of Illinois at Urbana-Champaign, however, uses light to automatically detect such cells within seconds.

Using a procedure known as Fourier Transform Light Scattering (FTLS), the researchers shined light on healthy, properly-shaped red blood cells, and analyzed how it scattered off of them. It turned out that the diameter and width of the dimples changed the light-scattering pattern significantly.

By applying a mathematical rule called the Born approximation, they were then able to determine what the scattering signature for healthy cells should look like. Now, when a blood sample is subjected to FTLS, pathologists should be able to quickly ascertain the state of its red cells, depending on whether or not it displays the right signature.

The University of Illinois team believe that the new technique could allow for quicker, more accurate blood tests, and that it could be particularly helpful in developing nations with few resources.

A paper on the research was recently published in the journal Biomedical Optics Express.