Clearly Better Light on Fluorescence Microscopy from Carl Zeiss

A high performance LED light source providing up to ten precise excitation wavelengths ideal for fluorescence microscopy has been launched by Carl Zeiss. Called Colibri, the computer-controllable unit will switch wavelengths in microseconds yet produces no heat or vibration, resulting in high contrast images rich in fine detail. The Colibri is ideally suited to replace metal halide light sources in all fluorescence microscopy applications, particularly in live cell imaging and other work with sensitive living specimens.

The intensity of the narrow-band LEDs (light emitting diodes) can be rapidly and accurately set for any wavelength, either from Zeiss’ AxioVision software or directly from the manual controller. This allows users to balance the intensity of multiple excitation wavelengths and capture the result in a single image rather than taking multiple colour images and then attempting to balance the comparative intensities in software. The fine control of intensity also offers maximum protection for specimens and the narrow emission band produces a high signal-to-noise ratio, which is particularly significant for the detection of weak signals and fine details. The reproducibility of the illumination conditions is particularly important in medical diagnostics where documentation is made in accordance with GxP guidelines.

Rather than switching between wavelengths using filters, the different LEDs in Colibri are opto-electronically switched at extremely high speed – an important asset in multi-wavelength and kinetic studies. Also, because no movement is involved, vibration is eliminated leading to accurate and highly resolved image capture.

LEDs convert electricity very efficiently into light and, unlike traditional light sources, the Colibri does not generate radiant heat. Therefore, microscope incubators can be used immediately without waiting for thermal conditions to stabilise and the minimisation of heat build-up results in more stable conditions during prolonged experiments. The full potential of Colibri is displayed in the Cell Observer HS high speed live cell imaging system.

Ten narrow-band LED modules offering wavelengths from UV to dark red and matching the most commonly used fluorescent dyes are currently available. Up to four may be installed in the Colibri at any time and changing the LED modules and beam combiners is a quick and simple job. This flexibility future proofs users’ investment in Colibri with future LED modules, both of new wavelengths or higher emissions, implemented easily and without complications. The Colibri’s long-life LED modules are equipped with ACR (automatic component recognition) ruling out the possibility of incorrect wavelengths being used during experimentation. The unit also incorporates a motorised coupler for an additional white light source for added flexibility.

The Zeiss Colibri will operate as a stand-alone unit on upright and inverted, manual and motorised microscopes but is also fully integrated into all versions of the AxioVision software.