What is the difference between ethidium bromide and SYBR Safe?

Ethidium bromide and SYBR Safe are both highly sensitive stains used for visualizing DNA in agarose or acrylamide gels. Both stains work by intercalating with DNA but there are a few major points of difference between the two.

Ethidium Bromide:

• Highly toxic as a mutagen
• Can be used in the gel or as a post-stain at a concentration of 0.5 mg/L
• Uses UV excitation in downstream applications

SYBR Safe:

• Less mutagenic than ethidium bromide but its acute toxicity is higher
• Used only as an in-gel stain
• Can utilize either blue light or UV excitation in downstream applications

SYBR Safe is generally used as a safer alternative to ethidium bromide in most agarose gel electrophoresis experiments.