Every blood cell has its own 'voice,' according to new research from Ryerson University that found red blood cells produce sound waves, which could be used to recognize their shape and size. The discovery yields a faster test for blood disorders like sickle cell anemia or malaria, and could eventually be used to diagnose a disease from a single drop of blood.

Size and shape are critical features for a red blood cell. Our smallest blood vessels are so thin that only one red blood cell can pass through at a time. Any slight deviation in blood cell morphology can damage the vessel and lead to dangerous clots. Misshapen blood cell are typically the result of 'wear and tear,' genetic conditions like sickle cell anemia, or infectious diseases like malaria.

Currently there are automated tools that doctors use to scan for appropriately sized cells, but examining shape, which is necessary to diagnose a particular disease, requires long hours behind a microscope, looking at individual cells.

Using sophisticated lasers, biomedical physicists at Ryerson have devised a strategy that measures the size and shape of red blood cells at once. The key to the technique is hemoglobin, the oxygen-carrying protein in red blood cells. When high intensity light strikes hemoglobin, it rapidly expands, leading to the emission of a sound wave. Using light to generate measurable sound waves is known as 'photoacoustics.'

The researchers teased out a method for using photoacoustics to map misshapen blood cells.

"Our technique is highly sensitive to small variations in RBC morphology," wrote the authors, led by Dr. Michael Kolios.

What's remarkable is very few cells, as little as 21, were needed to make a clinical description. Current standards require the examination of thousands of cells, which can be laborious if a doctor is looking at samples from a large group of people.

The next step is to pack the technology into a user-friendly device and potentially adapt the technique to looking at other types of cells, such as white blood cells.

"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 Kolios.

Source: Strohm EM, Berndl ESL, Kolios MC. Probing Red Blood Cell Morphology Using High-Frequency Photoacoustics. Biophysical Journal. 2013.