6X DNA Loading Buffer for Agarose

Contributed by <jt03@ic.ac.uk>

Easy to use, add 2ul per 10ul of DNA solution.

Ficoll 400 performs better than glycerol or sucrose based loading buffers.

EDTA and SDS are included as enzyme inhibitor and protein denaturant respectively, they help sharpen up bands a bit.

Orange G is the dye of choice as it won’t obscure smaller DNA bands like other dyes.


  1. Ficoll 400
  2. 0.5 M EDTA solution
  3. 10% SDS solution
  4. Ultrapure H20
  5. Orange G crystals


  • Combine the following in a 50ml falcon tube (you’ll need the extra space for mixing)
  1. 2.5 g Ficoll 400
  2. 400 ul 0.5 M EDTA
  3. 18 ul 10% SDS
  4. Ultrapure H2O to 10 mls
  • Add a small pinch of Orange G (Don’t use your fingers). You’re aiming for a deep orange colour.
  • Leave on a shaker/shaking incubator for an hour or so (it takes a while to dissolve)
  • Once dissolved it’s ready to use. Store at RT, lasts forever.