New 3D tracking microscope allows scientists to follow individual molecules in live cells

January 20, 2011—Scientists with the Center for Integrated Nanotechnologies have developed a 3D tracking microscope to follow three-dimensional movement of individual protein molecules inside live cells.

In an early demonstration, this instrument was used to follow three-dimensional dynamics of key proteins involved in the human allergic response and associated biological signals.

The microscope system simultaneously samples four spots surrounding the molecule under scrutiny and tracks both its spatial and temporal dynamics. To facilitate such tracking, these important signaling molecules are labeled with quantum dots, tiny glowing nanocrystals.

The system enjoys several advantages over other approaches to 3D molecular tracking:

• an increased tracking range that enables detection of biomolecular motion throughout the entire volume of many mammalian cells
• substantially lower damage to the cell in which the molecules reside
• the ability to perform time-resolved spectroscopy on the molecules being tracked.

The Center for Integrated Nanotechnologies is a user facility operated jointly by Los Alamos National Laboratory and Sandia National Laboratories for the U.S. Department of Energy’s Office of Basic Energy Sciences. The 3D tracking microscope team is led by Jim Werner and includes Peter Goodwin, Guillaume Lessard, and Nathan Wells.

Werner’s work on an earlier version of this technology, the world’s first confocal microscope capable of following the 3D motion of nanometer-sized objects, earned a 2008 R&D 100 award.

Funding for the studies in live cells is from the National Institutes of Health.