As any weekend warrior knows, an errant elbow or a missed ball can put a crimp in an afternoon of fun. The bruising and swelling are painfully obvious, but the processes occurring under the skin remain full of mystery. What is known is that leukocytes, or white blood cells, mobilize to protect injured body tissue from infection. What is not understood is why some leukocytes - but not others - are attracted to damaged tissue.

The response begins when leukocytes travel through blood vessels near the site of the injury and stop. Eight out of ten white blood cells will eventually continue traveling through the blood vessel, while the other two cells will actually enter the tissue to begin fighting against infection. Thanks to a $9.2 million grant from the National Institutes of Health, a research team led by Richard Waugh (Waugh Lab), Chairman of the Biomedical Engineering Department at the University of Rochester, is trying to find the reasons.

The project team includes: Minsoo Kim (Kim Lab) and Ingrid Sarelius of the University of Rochester; Michael King and Moonsoo Jin of Cornell University; Daniel Hammer of the University of Pennsylvania; and Micah Dembo of Boston University.

Watch the YouTube video of the research here.