Device Sees More inside Live Cells

The delicate touch of visible light allows scientists to peer into living cells without disrupting them. However, to discern the subtlest details, optical microscopes have long been considered too crude a tool. Instead, researchers have developed techniques such as electron microscopy to make out the finest features, but only in dead specimens.

Elongated region (above) where laser would excite fluorescence shrinks and becomes more spherical (below) when canceling pulse switches on.