GelRed

GelRed is a red-fluorescent nucleic acid stain used to visualize DNA during agarose gel electrophoresis. It is marketed as a safer alternative to ethidium bromide and is a bis-intercalating dye that binds to double-stranded DNA. When bound to DNA, GelRed emits bright red fluorescence under ultraviolet or blue-light illumination, enabling visualization of separated DNA fragments.

GelRed is designed to have limited permeability through intact cell membranes, which is claimed to reduce mutagenic risk compared with ethidium bromide. This property is emphasized as contributing to lower exposure risk for users and reduced environmental impact, though standard lab safety practices and proper disposal remain important.

In practice, GelRed can be used by adding it to the gel before casting (pre-stain) or by post-staining the gel after electrophoresis. Concentrations and protocols vary by product and should follow the manufacturer’s guidelines. GelRed is compatible with common gel documentation systems and can be visualized with UV transilluminators or with blue-light transilluminators that filter UV.

GelRed is produced and marketed by Biotium, and is part of a family of DNA stains that includes related dyes such as GelGreen. It is widely used in molecular biology laboratories as an alternative to traditional ethidium bromide staining, providing a balance of sensitivity and safety within standard gel electrophoresis workflows.