FLIM-Fluorescence Lifetime Imaging Microscopy
Fluorescence Lifetime Imaging -FLIM
The LIFA -Lambert Instruments Fluorescence Attachment for lifetime imaging microscopy can be attached to any widefield fluorescence microscope and works in the frequency domain, which means that it uses a modulated light source and a modulated image intensifier as detector. The system is easy to install (within 1 hour) and to operate and does not require an optical bench with laser. The LIFA -Lambert Instruments Fluorescence Attachment system has been judged "easy and highly quantitative". And last but not least, it's reasonable priced.
Digital CCD camera
Integrated Control unit / Signal generator / Power supply
LI FLIM software
An image intensifier is a device that intensifies low light-level images to light levels that can be seen with the human eye or can be detected by a video camera. An image intensifier is a vacuum tube, having an input window on which inside surface a light sensitive layer called the photocathode has been deposited. Photons are absorbed in the photocathode and give rise to emission of electrons into the vacuum. These electrons are accelerated by an electric field to increase their energy and focus them. After multiplication by an MCP (multi channel plate) these electrons will finally be accelerated towards the anode screen. The anode screen contains a layer of phosphorescent material that is covered by a thin aluminium film. When striking the anode the energy of the electrons is converted into photons again. Because of the multiplication and increased energy of the electrons the output brightness is higher as compared to the original input light intensity.
The different "generations" of image intensifiers are described here:
First Generation Image Intensifier
Second Generation Image Intensifier
Another important feature of the second-generation image intensifier is gating.
>The advantages of a second generation image intensifiers are:
For FLIM-Fluorescence Lifetime Imaging Microscopy, a second-generation image intensifier is used as the detector of the system for lifetime imaging. The image intensifier, combined with a CCD camera, is attached to the widefield fluorescence microscope. The photocathode of the intensifier is located in the image (focal) plane of the microscope. In the frequency domain FLIM system the photocathode is switched from positive to negative at the same frequency as the light source is modulated.
Third Generation Image Intensifier