[Video] Filopodia waving on the surface of a HeLa cell 
CREDIT: Liang Gao, Eric Betzig, Janelia Farm

As biologists advance their quest to understand life, they need more advanced optical tools to look inside cells at ever-smaller dimensions. There is a hundred-fold gap, for example, between the smallest features conventional optical microscopy can visualize and the scale at which molecules self-assemble to form structures within cells. 

In a symposium at the AAAS Annual Meeting devoted to new advances in single molecule detection and cell imaging technology, Eric Betzig, a physicist at the Howard Hughes Medical Institute in Ashburn, Va. described the marriage of two recent microscope technologies, called structured illumination and Bessel beam plane illumination. 

The result allows biologists to rapidly and noninvasively image the three-dimensional dynamics of living cells at spatial resolution beyond the conventional limits. Betzig presented  a human cervical cancer cell and the waving protrusions on its surface, called filopodia, that the cell uses to sense its surroundings.