K2 Direct Detection Camera
High performance EM and cryo-EM camera
[testimonial author=”Subramaniam, S., Kuhlbrandt, W. & Henderson, R. (2016). IUCrJ 3, 3-7″]At present only the Gatan K2, when operated in counting mode, can produce a DQE(0) as high as 80% in conjunction with reasonably small exposure times. The K2 detector frame rate is about 10 times higher than that available with the two other detector brands.[/testimonial]
The K2 Summit electron counting direct detection camera is the highest performance detector available for cryo-electron microscopy (cryo-EM). The unmatched frame rate enhances both contrast and resolution for large and small molecules alike.
- Unmatched DQE (detective quantum efficiency) up to 80%
- Used for ground-breaking structural cryo-EM discoveries
- Best resolution and contrast
- High resolution imaging below 500 kDa
- Resolve differences with heterogeneous samples
- High quality cryo-tomography
- 4x larger area in each image, with super-resolution mode
Direct Detection vs Traditional Cameras
The resolution of a traditional EM camera is limited by electron and photon scattering in the scintillator or fiber optics, or by the inherent limitations of lens coupling. When it enters the camera, each electron event is delocalised into a cloud of light. This point spread function (PSF) exacerbates at higher beam energies. Image quality is further limited n traditional cameras by noise from statistical variation in electron scattering and the energy deposition processes, read noise from the camera electronics and from distortion and fixed patterns from the fiber optics or softening caused by lenses.
Direct detection cameras receive electrons directly onto the sensor. This eliminates the need for scintillators, fibre optics and lenses and also greatly reduces PSF. In counting modes, noise can be essentially eliminated. With the transmission sensor, the number of scattered electrons re-entering the detector from below is kept to an absolute minimum.
A unique capability of the K2 Summit 4k x 4k direct detection camera is counting individual electrons, rather than traditional integration of their analogue signal. The K2 Summit has unmatched sensitivity and DQE, which are the main measures for judging and comparing high resolution EM cameras.