Time for your close-up
by Randall C Willis  |  Email the author

WORCESTER, Mass.—The ability of a cell to repair damage done to its genetic material is key to cell survival and often serves as the line between healthy and diseased tissues. Imaging limitations, however, have made it difficult to get a detailed understanding of biological repair mechanisms at the molecular level. Recently, researchers at the UMass Medical Center, The Jackson Laboratory and Leica Microsystems pushed these limits.
In a recent PNAS, the researchers used immunofluorescence to monitor the action of key histone proteins in response to DNA damage caused by exposing cells to carcinogens. In particular, they used a high-resolution confocal microscopy system called 4Pi microscopy, which uses two objectives to look at the same spot and thereby allows researchers to resolve objects (in the z-axis) below 100 nm.
The researchers noted that within seconds of DNA damage, the histones were phosphorylated and formed clusters, which the researchers speculate may provide a mechanism for signaling and repair protein assembly. "We look forward to continuing our investigations with the analysis of other nuclear proteins involved in cancer prevention and the repair of DNA damage," said UMass researcher Dr. Brian Bennett.