Q-banding in chromosomes

Staining of chromosome segments with a Quinacrine mustard solution allow to identify specific chromosomes and structural rearrangements. The present case study describes an illuminator for epi- fluorescence microscopy were the traditional arc-lamp is replaced by a Light Emitting Diode. The illuminator can be employed even on microscopes already placed in the laboratory.


In modern fluorescence microscopy, Light Emitting Diodes (LEDs) offer a compelling advantage to traditional light sources for several reasons: no frequent replacement of light source, reduced heath production (very important in case of laboratories with many microscopes), no warm-up time and no misalignment of light source due to electrode consumption, just to mention a few. The particular geometry of these solid state light sources, very different from gas vapour lamps, require an optimized design of the reflected light path in order to deliver clear high quality images with the objectives typically used for this application. Therefore FLUOLED® 1CFW (1 Colour Filter Wheel) reflected light illuminator represents a fast and reliable solution for fluorescence microscopy using light emitting diodes (LEDs) as a source for excitation. Different from other LED devices for fluorescence microscopy, FLUOLED® 1CFW includes a complete reflected light illuminator.

FLUOLED® 1CFW and 3CFW: 1 Colour and 3 Colour Filter Wheel reflected light illuminators for the detection of Quinacrine banding patterns in chromosomes.

FLUOLED® 1CFW (1 Colour Filter Wheel) and FLUOLED® 3CFW (3 Colour Filter Wheel) combine the advantages of LED illumination with the optimization of the FLUOLED reflected light path, delivering clear high quality images with the objectives typically used for this application. Different from other LED devices, FLUOLED® 1CFW and 3CFW do not require an existing epi-fluorescence illuminator mounted on the microscope, so fluorescence becomes available even on microscopes where original accessories are not manufactured any more. The Royal Blue LED proved to be an optimized light source for Quinacrine mustard stained chromosomes. In addition the illumination can be set to a safe 50% intensity with reduced risk of bleaching out the metaphase before acquiring the final digital image at full intensity.


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FLUOLED® 3CFW on Olympus BX43 microscope. Digital camera: Lumenera Infinity 2-1C. Q-bands obtained with Royal Blue 450 nm LED excitation.


The use of a high power solid-state (LED) source enabled increased performance, significantly increased light source lifetime, reduction of initial costs and operating costs, and reduction of maintenance and heat production. Main FLUOLED® 1CFW & 3CFW product benefits are:

  • Light source lifetime: typically 30.000 hours, thus allowing many years of operation and cost savings.
  • No need of any special alignment procedure.
  • No warm-up time required for the light source.
  • Additional LED sources and filter sets can be added to the system at any time.
  • Reduced heath emitted by the light source: very important in case of laboratories with more work stations.