Belfast, Ireland-- Two back illuminated Andor EMCCD cameras—the DU860, which is capable of acquiring images at 500 frames per second, and the DU897, which can capture individual photons from single fluorescence emitters—have been instrumental in helping Steven Chu, a Nobel laureate and Energy Secretary for the United States, redraw the boundaries of optical microscopy.1 By developing an active feedback system, Chu and his team were able to repeatedly place the centroid of a single fluorescent molecule image anywhere on either of the camera’s CCD arrays and measure its position with sub-pixel accuracy. This means that in conjunction with additional optical beams to stabilize the microscopy system, the traditional errors caused by non-uniformity of chip manufacture can be reduced to sub-nanometer scale.
As a result, Chu and his colleagues developed a two-color, single molecule imaging system, which achieved image resolutions with an order of magnitude greater than the current best super-resolution techniques (5 nm). The team plans to harness the new technique to learn more about the human RNA polymerase II system, which initiates the transcription of DNA, and the molecular mechanisms controlling cell-to-cell adhesion processes.
The resolving power of this new super-resolution technique may also be of great use in guiding the design of new photometric imaging systems in nanometrology, atomic physics and astronomy.
1. A. Pertsindis, Y. Zhang, S. Chu: "Subnanometre single-molecule localization, registration and distance measurements." Nature, doi:10.1038/nature09163 (2010).