Most research labs use DNA stains that are visualized with UV light. These stains are more sensitive that dyes or stains such as methylene blue or crystal violet, so allow the use of smaller amounts of DNA and usually quicker staining. The stained gel is placed on the surface of a UV transilluminator and then the stain flouresces brightly when it is bound to DNA. For many years, ethidium bromide (EtBr) was the standard DNA stain. It is cheap, quick, and sensitive. However it is also a mutagen, so both the stain and any items used with it present clean up and "disposal" problems.
New fluorescent DNA stains are now available that are much safer (usually assayed with the Ames test on bacteria). SEP has used several of these from the SYBR series of dyes. Currently we are using SYBR Safe from Molecular Probes/Life Technologies. Additional information on this stain, its use, safety, etc is available at the company's website with this long URL:
and this 4 page product manual
For staining gels after the electrophoresis run:
Wear gloves and use a spatula to handle gels. Place the gel in a plastic tray (not glass). Add sufficient stain to cover the gel, probably 30 ml. Incubate for 30 minutes. Protect the gel and stain from light by covering with foil or placing in the dark. Continual agitation on a shaker is recommended. No destaining is required. Used stain can be returned to SEP.
Stock SYBR Safe concentration: 10,000X (therefore dilute 20 microliters of stain into 200 ml of 1 X TAE) and store in brown bottle provided.
Storage: 2-25°C, protected from light. Stable about 6 months.
Excitation maxima: 280, 502 and emission maximum 530 nm when bound to DNA
EMBI Tec MiniOne Gel Electrophoresis System with built in real time imaging
Notes from SEP Lead Teacher Greg Ballog, summer 2014. Greg also has experience with newer blue light systems for visualizing gels. We plan to add that information soon.