Weiner never expected to find this robust wave motion, and until recently, he would not have been able to visually capture it using a light microscope. And even now that the technology to do so exists, such advanced tools are typically limited to the very fortunate and few. At U.C.S.F., there is a plan to change that.
Sitting by his laptop on the Mission Bay campus, Orion Weiner of the University of California, San Francisco, is watching a movie of an immune cell called a neutrophil scurrying across his computer screen. The movie, made with a conventional optical microscope, reveals that a fuzzy vanguard of proteins is driving the neutrophil. But when he opens a second movie file of the motion, this one made with a more advanced light microscopy technique called total internal reflection fluorescence (TIRF), the vanguard no longer appears as one solid front of proteins but rather as a wave of individual proteins pushing forward like ripples from a pebble in a pond.