CCD cameras – the previous gold standard
Since the inception of digital microscopy, scientific grade CCD cameras have been the gold standard for imaging due to their sensitivity, linear response to light and low noise characteristics. However, while CCDs are great for low-light fluorescence documentation and quantitation, the inherent architecture of these sensors limits their ability to achieve high frame rates in combination with low noise and high resolution.
In recent years, cell biology research has emphasized live cell dynamics, mechanisms and electrochemical signalling. As this research probes deeper into investigating rapidly changing phenomenon, the need for measuring high-speed events at low light is constantly increasing. This trend highlights a limitation in the effectiveness of CCD cameras which are not able to capture these dynamic biological events with sufficient temporal resolution while preserving high signal-to-noise and spatial resolutions.
Enter sCMOS technology
With the introduction of scientific grade Complementary Metal Oxide Semiconductors (sCMOS) cameras, achieving high speed imaging in combination with high resolution and high signal-to-noise is now possible. The unique architecture of sCMOS sensors combine low electronic noise that’s nearly one third of most high end interline CCD cameras with nearly 10x the frame-rate potential. These two factors alone offer considerable advantages to traditional CCD cameras for most live cell fluorescence microscopy applications.
Choosing a CCD or sCMOS camera depends on the application
As with anything, deciding whether a CCD or a sCMOS based camera is a better choice depends on the application. The prevailing factor to consider when deciding between a CCD or sCMOS camera is exposure time. Applications that require long exposure times ranging from a few minutes to a few hours are still best served by CCD cameras due to their lower dark current. These applications include bioluminescence and chemiluminescence from Western blot gels or in vivo animal imaging or electroluminescence from semiconducting materials.
Fluorescence applications that can afford longer exposure times, including immunofluorescence of fixed cells, are well served by both sCMOS and CCD cameras. Considering these samples are not particularly sensitive to the effects of photobleaching, most researchers can afford to increase exposure times to several hundred milliseconds with an inexpensive CCD camera. That stated, the lower noise of sCMOS combined with its higher frame rates do provide higher-quality images with shorter exposure times and a frame rate that makes it much easier to scan and focus on the sample.
Fluorescence imaging of living cells on the other hand is extremely sensitive to light exposure. Controlling light and camera exposure of the cell is required to both minimize the photobleaching and phototoxicity effects as well as capture as much temporal information as possible. For this application, the high frame rates and substantially lower noise provided by sCMOS sensors offer significant advantages over CCDs and is therefore best served by sCMOS cameras.
sCMOS from QImaging
Understanding this need for researchers to obtain higher quality data from dynamic cellular events, QImaging, a scientific camera company for the bio research industry, has recently introduced the optiMOS sCMOS camera as the CCD replacement for live cell applications. optiMOS is capable of streaming 100 fps with a 45% larger Field of View and < 2e- of read noise, delivering 10x the time resolution of typical CCD cameras without trading off on resolution or sensitivity. Offered as the affordable sCMOS solution, optiMOS brings the advantages of low noise and high speed imaging to a broader range of cell biology applications.
While there is a wide range of imaging applications with varying camera requirements, it is clear that the advances in sCMOS technology significantly improves the bio researchers ability to capture and study live cell events. optiMOS aims to provide these imaging benefits to even the most budget constrained labs in hopes of further advancing the scientific community’s understanding of the role of cellular dynamics.
If you’d like to learn more about which camera technology is best suited for your research, additional information, including a new whitepaper, is available online.