There are two significant challenges in biological imaging that conventional fluorescence microscopy cannot overcome.
Firstly, biological specimens are 3-dimensional structures so to fully understand them we often need to construct 3-dimensional images. Secondly, many processes biologists would want to study occur inside biological structures, but other cell features such as the cell membrane block a clear view.
These problems are difficult to overcome due to the need to pass light through the entire sample to illuminate the chosen image plane. This gives no control over where within the light path the returning light comes from. Light from out of focus planes, and from bright features above and below the desired plane cannot be blocked with conventional fluorescence microscopy.
Confocal microscopy offers the solution to this issue.
Confocal microscopy uses optical sectioning to take multiple, thin, 2-dimensional slices of a sample to construct a 3-dimensional model from them. This process removes the out-of-focus light from other planes.
Compared to other optical sectioning techniques, spinning disk confocal microscopy is highspeed, high-sensitivity and simple to implement. This makes it a very common choice for studying 3-D structure, fast dynamic processes, long-term time-lapse or details inside the cell membrane, all possible with live cells.
Spinning disk microscopy is, however, a light rejection technique so a high photon budget is necessary for high-quality imaging.
Conventional spinning disk confocal microscopy uses a dual disk strategy to increase the amount of light reaching the sample by focusing the excitation light through microlenses on the first disk into the pinholes of the second disk. Emission light then passes back through the second disk and onto the camera.
The use of two disks and microlenses is, however, expensive.
CrestOptics changes this by introducing the X-Light confocal imager; a spinning disk system with a proprietary single disk pinhole design with high light collection efficiency without microlenses to create an affordable spinning disk confocal system.