6X DNA GEL loading buffer

Based on Red Book, page 2.51.5 Supplement 51

In the sample that goes on the gel these are the concentrations:

• 2 % by weight FICOLL 400 or 2% glycerol by volume
• 10 mM Na2EDTA, pH 8
• 0.1% by weight SDS
• 0.025% by weight bromphenol blue (this is obviously too muchÉ use 0.0005%)
• 0.025% by weight xylene cyanol (this is obviously too muchÉ use 0.0005%. This buffer is optional, good when there are high MW bands)

The concentrations in 6X buffer are:

• 12% FICOLL 400 by weight or 12 % glycerol by volume.
• 60 mM Na2EDTA, pH 8
• 0.6% by weight SDS
• 0.003% by weight bromphenol blue
• 0.003% by weight xylene cyanol (optional, good when there are high MW bands)

To make 10 mL of 6X

• 1.2 g FICOLL 400 from solid or 1.2 mL glycerol
• 1.2 mL 0.5 mM disodium EDTA (stock in 50 mL Falcon tube on bench labeled 0.5 M EDTA)
• 300 uL of a 20% SDS stock in a 250 mL bottle at RT
• 60 uL of 0.5% BFB stock (a stock is stored as a slurry on the benchtop in a 15 mL falcon tube).
• 60 uL of a 0.5% xylene cyanol stock that I will make now.
• Water up to 10 mL ( about 7.2 mL).

0.5 % xylene cyanol stock

10 mL 0.5% xylene cyanol. Add 50 mg to 10 mL water.