Didcot, England--A new process for using laser tweezers developed at the Science and Technology Facilities Council's (STFC's) Rutherford Appleton Laboratory will help streamline protein microcrystal selection for biosciences research. Protein microcrystals enable researchers to analyze the structure of molecules and how they behave, for example in disease. The results are published in Acta Crystallographica D this week.
The technique allows researchers to select and place the crystals on customized sample holders for crystallographic analysis on one of the structural-biology x-ray beamlines at Diamond Light Source, the UK’s national synchrotron science facility.
Microfiber net holds crystals
The laser-tweezing technique is the result of a collaboration between Diamond Light Source and STFC's Central Laser Facility (CLF) and Technology departments. In this area of research, crystals of proteins rather than single molecules must be used, but for many proteins, the crystals can be so small (less than 10 μm) that they are difficult to handle and mount onto standard sample holders. In the new approach, a microfiber web forms a net for the crystals to be mounted on. Laser tweezers are then used to grab the crystals and move them onto the sample holders.
Armin Wagner, project lead at Diamond Light Source, explains why this technique is so important. “Previously we have, in essence, wasted two to three days on the beamline just looking for our best crystals," he says. "Now, using the laser-tweezers system, we can visually identify and select specific crystals and transfer them to well-defined positions on a sample mount rather than relying on a purely random process.”