Red blood cells struck with laser light generate high-frequency sound waves that could help researchers differentiate normal cells from abnormal ones to diagnose blood disorders. Deviations from the regular biconcave shape of a red blood cell are a significant indicator of such diseases, whether they result from genetic abnormalities, infectious agents or simply a chemical imbalance. For example, the red blood cells of patients with malaria are irregularly swollen, while those with sickle cell anemia take on a rigid sickle shape. Investigators at Ryerson University are using a photoacoustic microscope that detects sound waves to reveal information about the size and shape of red blood cells. Gathering information from a 21-cell sample takes only fractions of a second and could aid in the development of simple tests requiring only a single drop of blood. Researchers at Ryerson University say they can analyze the sound waves produced by red blood cells to distinguish their shapes and sizes, which could help in the development of simple diagnostic tests. Courtesy of Strohm et al, Biophysical Journal. “We plan to make specialized devices that will allow the detection of individual red blood cells and analyze the photoacoustic signals they produce to rapidly diagnose red-blood-cell pathologies,” said senior author Dr. Michael Kolios. The researchers are now working to develop a microfluidic device that integrates the laser and probes to flow single cells through a target area. “This would enable measuring thousands of cells in a very short period of time with minimal user involvement,” said first author Eric Strohm, a graduate student in Kolios’ laboratory. The method is also being applied to other types of cells: One example is white blood cells, in which changes in photoacoustic signals could indicate the formation of dangerous clots. The research appeared in Biophysical Journal (doi: 10.1016/j.bpj.2013.05.037).