Prepare resolving gel and stacking gel casting solutions. The table below gives the formulations for Native resolving gels from 6 - 12% as well as the formulation for the stacking gel.

Resolving gel buffer (4x):	1.5M Tris HCl pH 8.8
Stacking gel buffer (4x):	0.6M Tris HCl pH 6.8
Running (tank) buffer (10X):	1.92M Glycine, 0.25M Tris, pH 8.3

Formulate enough resolving gel solution to fill the cassette and formulate 1/5 that amount of stacking gel solution. De-gas the solutions for optimum reproducibility. Stir the solution under aspiration for 10 minutes at room temperature.

Pour the resolving gel:

Add 0.1ml of fresh 10% Ammonium Persulfate (APS) solution for every 10ml of casting solution. Swirl gently to mix. Add 10 µl of TEMED for every 10ml of casting solution. Swirl gently to mix. Pour the solution into the gel cassette. Fill the cassette to a level which will allow the comb to be inserted with 5mm between the bottom of the wells and the top of the resolving gel. Overlay the gel with 1-2mm of water saturated n-butanol to exclude O2 and ensure a flat interface between the resolving and stacking gels. Allow the gel to polymerize for 30 minutes. A line will become visible at the top of the gel as it polymerizes.

Pour the stacking gel:

Rinse the butanol from the top of the gel with water, and drain the water by inverting the gel. Add 0.1 ml of 10% APS and 10 µl TEMED for every 10 ml of stacking gel solution and fill the top of the cassette with this mixture. Insert the comb until the teeth are 5mm from the resolving gel. The comb should rest so that the tops of the well dividers are level with the top of the short plate. This excludes oxygen while ensuring that the dividers will fully separate the wells. Allow the stacking gel to polymerize for 30-60 minutes. Run the gel in 1X Tris-Glycine buffer (see above).