Back-illuminated electron multiplying technology: The world's most sensitive CCD for ultra low-light microscopy

摘要

The back-illuminated Electron Multiplying Charge Coupled Device (EMCCD) camera stands to be one the most revolutionary contributions ever to the burgeoning fields of low-light dynamic cellular microscopy and single molecule detection, combining extremely high photon conversion efficiency with the ability to eliminate the readout noise detection limit. Here, we present some preliminary measurements recorded by a very rapid frame rate version of this camera technology, incorporated into a spinning disk confocal microscopy set-up that is used for fast intracellular calcium flux measurements. The results presented demonstrate the united effects of: (a) EMCCD technology in amplifying the very weak signal from these fluorescently labelled cells above the readout noise detection limit, that they would otherwise be completely lost in; (b) back-thinned CCD technology in maximizing the signal/shot noise ratio from such weak photon fluxes. It has also been shown how this innovative development can offer significant signal improvements over that afforded by ICCD technology. Practically, this marked advancement in detector sensitivity affords benefits such as shorter exposure times (therefore faster frame rates), lower dye concentrations and reduced excitation powers and will remove some of the barriers that have been restricting the development of new innovative low-light microscopy techniques.