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.