Distinguishing single cells with nothing...( Researchers at the University of Roc...)

Researchers at the University of Rochester have developed a novel optical technique that permits rapid analysis of single human immune cells using only light.

Availability of such a technique means that immunologists and other cellular researchers may soon be able to observe the responses of individual cells to various stimuli, rather than relying on aggregate statistical data from large cell populations. Until now scientists have not had a non-invasive way to see how human cells, like T cells or cancer cells, activate individually and evolve over time.

As reported today in a special biomedical issue of Applied Optics, this is the first time clear differences between two types of immune cells have been seen using a microscopy system that gathers chemical and structural information by combining two previously distinct optical techniques, according to senior author Andrew Berger, associate professor of optics at the University of Rochester.

Berger and his graduate student Zachary Smith are the first to integrate Raman and angular-scattering microscopy into a single system, which they call IRAM.

"Conceptually it's pretty straightforwardyou shine a specified wavelength of light onto your sample and you get back a large number of peaks spread out like a rainbow," says Berger. "The peaks tell you how the molecules you're studying vibrate and together the vibrations give you the chemical information."

According to Smith, "Raman spectroscopy is essentially an easy way to get a fingerprint from the molecule."

Structural information is simultaneously gathered by examining the angles at which light incident on a sample is bumped off its original course.

Together the chemical and structural information provide the data needed to classify and distinguish between two different, single cells. Berger and Smith verified this by looking at single granulocytesa type of white blood celland peripheral blo
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