New imaging technique measures disease at cellular level
Researchers at Massachusetts Institute of Technology (MIT) have developed an imaging technique that can create 3D images of living cells and measure the frequency at which red blood cells vibrate.

The work was performed in collaboration between MIT physicist Michael Feld and Subra Suresh, dean of MIT's school of engineering and a materials scientist. Feld heads MIT's Laser Biomedical Research Center, where Suresh's team conducts experiments to measure the stiffness of red blood cells infected by malaria parasites, according to MIT Technology Review.

To measure the cells' nanoscale vibrational frequencies, the researchers combined Feld's imaging technique, which stitches multiple images together into a composite, with diffraction phase microscopy, in which a laser beam that passes through a cell rejoins a reference beam that does not, creating a distinctive interference pattern.

Vibrating cell membranes move mere nanometers at a time, and those movements take place in microseconds. Ares Rosakis, professor of aeronautics and mechanical engineering at the California Institute of Technology in San Marino, who was not involved in the work, said that imaging with interference patterns is particularly challenging when looking at red blood cells, which are doughnut-shaped and fluid, constantly changing shape in all directions.

To establish the connection between the cells' vibration and their health, the researchers used Feld's technique to create 3D images of a malarial parasite inside a red blood cell. They also measured the levels of hemoglobin inside the cells during various stages of a malarial infection.

Rosakis said that he see two potential uses for the new technique—to improve computer models of cells and improved diagnostics.

Eventually, a technique like Feld and Suresh's might provide a way to detect malaria as it's happening, reported MIT Technology Review. It takes 48 hours for a malarial invader to run through its life cycle, developing, reproducing, and being expelled from the cell. The researchers thus evaluated infected cells from each stage of that 48-hour process, at temperatures that simulated the fever and cooling that the human body experiences during a malarial infection.

Suresh and Feld said the study’s results will be published in the Proceedings of the National Academy of Sciences.