Highly read on www.cell.com 1–14 July

In less than a second, a laser pulse can show whether a red blood cell is squashed, swollen or abnormally shaped — all of which can signal disease or infection.

Eric Strohm and his colleagues at Ryerson University in Toronto, Canada, showed that when struck with a laser beam, red blood cells emit sound waves — albeit of a frequency too high for human ears to hear. Researchers used the amplitudes and frequencies of the waves to accurately determine the size and shape of these cells. The technique may one day be useful for diagnosing chemical imbalances, malaria, certain types of anaemia or other blood-related disorders, the authors say.

Biophys. J. 105, 59–67 (2013)