What is the concentration of ethidium homodimer-1?

Concentration of Ethidium Homodimer-1

Ethidium Homodimer-1 (EthD-1) is a fluorescent dye commonly used in molecular biology for the detection of nucleic acids in various applications, including fluorescence microscopy and flow cytometry. The concentration of EthD-1 used in experiments can vary depending on the specific application and the sensitivity required.

For staining DNA in agarose gels, a typical concentration range might be from 1 to 5 µM. In cell viability assays, where EthD-1 is used to identify dead cells by penetrating damaged cell membranes and binding to DNA, concentrations in the range of 1 to 4 µM are commonly used. It's crucial to optimize the concentration for each specific application to ensure accurate results without excessive background fluorescence.

Due to its high affinity for DNA, EthD-1 is very effective at low concentrations. However, it's important to handle it with care, as it is a potent mutagen and can intercalate into DNA, potentially causing mutations.

Preparation and Usage

To prepare a stock solution, EthD-1 is typically dissolved in water or an appropriate buffer to a concentration of 1 mM. This stock solution can then be diluted to the desired working concentration for the experiment. It's essential to protect the solution from light to prevent photobleaching of the dye.

When working with EthD-1, always wear appropriate protective equipment, including gloves and safety glasses, to avoid exposure.