In the community of localization-based super-resolution microscopy (or called localization microscopy), it is generally believed that the emission of single molecules is so weak that an EMCCD (electron multiplying charge coupled device) camera is necessary to be used as the detector by eliminating read noise. Here we evaluate the possibility of a new kind of low light detector, scientific complementary metal-oxide-semiconductor (sCMOS) camera in localization microscopy. We demonstrate experimentally that sCMOS is capable of imaging actin bundles with FWHM diameter of 37 nm, evidencing the capability of sCMOS in localization microscopy. We further characterize the noise performance of sCMOS and find out that, with the use of a bright fluorescence probe such as d2EosFP, localization microscopy imaging is now working in the shot noise limited region.

Localization-based super resolution microscopy holds superior performances in live cell imaging, but its widespread use is thus far mainly hindered by the slow image analysis speed. Here we show a powerful image analysis method based on the combination of the maximum likelihood algorithm and a Graphics Processing Unit (GPU). Results indicate that our method is fast enough for real-time processing of experimental images even from fast EMCCD cameras working at full frame rate without compromising localization precision or field of view. This newly developed method is also capable of revealing movements from the images immediately after data acquisition, which is of great benefit to live cell imaging.

Nowadays, there is a hot debate among industry and academic researchers that whether the newly developed scientific-grade Complementary Metal Oxide Semiconductor (sCMOS) cameras could become the image sensors of choice in localization-based super-resolution microscopy. To help researchers find answers to this question, here we reported an experimental methodology for quantitatively comparing the performance of low-light cameras in single molecule detection (characterized via image SNR) and localization (via localization accuracy). We found that a newly launched sCMOS camera can present superior imaging performance than a popular Electron Multiplying Charge Coupled Device (EMCCD) camera in a signal range (15-12000 photon/pixel) more than enough for typical localization-based super-resolution microscopy.