Principle

Fast and easy decontamination of ethidium bromide (EtBr) or SYBR® Green solutions

The most convenient method to visualize DNA in agarose gels is staining with the fluorescent dye ethidium bromide:

This substance intercalates between the double helix of nucleic acids resulting in a higher fluorescence in comparison to the dye in free solution. Because the fluorescence yield of ethidium bromide-DNA complexes is much greater than that of unbound dye, even small amounts of DNA can be detected in the presence of ethidium bromide. The only disadvantage of this very sensitive detection method is the dye itself. Ethidium bromide is a powerful mutagen and a toxic compound. The incubation of ethidium bromide with nucleic acids leads to deletions and insertions of nucleotides, resulting in frame mutations. This means that everybody handling this dye has to work very carefully and has to collect all buffer that contains ethidium bromide separately. Finally, the buffer has to be disposed of under special conditions. The decontamination and removal of ethidium bromide waste is often a time-consuming and expensive procedure.

In order to save time and money MACHEREY-NAGEL has developed the bondEX EtBr cartridges. The prefiltered ethidium bromide containing solution is simply poured onto the cartridge resulting in a flow through free of ethidium bromide (filters for clarification of solutions included in the kit). For larger volumes a 1 liter funnel can be connected to the top of the cartridge. Up to 50 mg of ethidium bromide can be adsorbed onto the bondEX EtBr cartridge. A removable indicator cartridge signalizes saturation of the bondEX cartridge by red color or UV fluorescence (see figure). The bondEX EtBr cartridges are recommended for the extraction of ethidium bromide from diluted EtBr solutions like TAE or TBE gel buffer as well as for more concentrated solutions.