DR Transilluminator

Clare Chemical Research are based in Colorado, USA and for over 20 years have developed innovative DNA visualisation tools. Their pioneering Dark Reader transilluminators have provided scientists worldwide with a safe and efficient means of visualising and excising bands from their agarose gels.

Dark Reader: Safe for you, safe for your precious nucleic acid samples

• Safe, visible blue light technology
• No UV, therefore No DNA damage
• Substantially improved cloning and transfection efficiencies
• Minimised photo bleaching
• No heat build up, therefore No DNA damage or gel drying out
• Improved sensitivity with key dyes due to improved transmission of light through plastics
• Cut your bands out in safety with no need for safety visors, protection or ‘Keep Out’ signs

How it works

Many popular dyes / fluorophores have their excitation maxima between 400-500 nm. The light sources in the Dark Reader emit within this range, which is shifted from the typical UV excitation peak of around 300 nm. The Dark Reader uses two filters to enable you to visualise your bands. The first filter sits between the LED light sources and the DNA, and acts to remove red and green components of light to ensure that only blue excitation light reaches the sample. The second amber coloured filter sits between the sample and the user to remove the blue excitation light but only allow the emitted light through. This combination allows you to clearly visualise your samples with excellent sensitivity in safety.

Which dyes / fluorophores does it work with?
The Dark Reader generally works well as long as the following two criteria are met:

A portion of the excitation spectrum lies between 420-500 nm
A portion of the emission spectrum lies above 520 nm

The following typical ‘Safe nucleic acid stains’ work well on the Dark Reader:

• GelGreen (Biotium) – Typically 0.5 ng dsDNA by eye
• SYBR Gold – Typically 100 pg dsDNA by eye
• SYBR Green – Typically <100 pg dsDNA by eye
• SYBR Safe – Typically 1 ng dsDNA by eye
• Ethidium Bromide can be used but generally detection limits are lower than when visualising using UV due to high background from unbound EtBr. This background can be reduced by lowering the concentration of EtBr used to stain the gel, and then it is possible to visualise by eye ~5 ng dsDNA when in a darkened room.

The Dark Reader has been used with great success to visualise eGFP, RFP, fluorescein as well as a range of protein stains including SYPRO Ruby and SYPRO Orange. For these applications Clare Chemicals also produce a compact handheld Dark Reader Lamp which has a focused excitation beam.