- Reduce the amount of sample DNA loaded to 60 to 125ng, and use 0.5X SYBR or GelRed dye in precast gels. These dyes are much more sensitive than EtBr. Blown out or smeared bands can be caused by overloading.
- It is preferable to wait a few minutes to add the SYBR or GelRed dyes to the molten agarose. Adding it to a cooled agarose solution (above gelling temperature, 45°C) produces better results.
- Always run a freshly made agarose gel, for a single run only. Re-running the gel will yield poor results.