New Tool Images Cells in Living Tissues

U.S. biologists said a tool called two-photon laser-scanning microscopy is enabling them to track and image the movement of cells inside living tissues.

The imaging tool is going to change how biological science is done, said scientists at the University of California in Berkeley who are using the new technique. In the past, biologists could only observe a single layer of cells, but the two-photon imaging system enables them to monitor and videotape the behavior of cells in an intact organ or tissue.

The system already has allowed them to observe the movement of immune system cells after they receive a signal to deal with a foreign invader, the scientists reported in the Public Library Of Science-Biology.

The system uses an infrared laser to hit a dye molecule with two photons of light, the key being that each photon is less energetic with longer wavelengths than that used by older imaging techniques, so they are able to penetrate deeper into the tissues.