40% Acrylamide (for DNA sequencing)(1 liter)
- Weigh out 380 g acrylamide (DNA-sequencing grade) and 20 g N,N?/EM>-methylenebisacrylamide.
<CAUTION> Acrylamide is a potent neurotoxin and is absorbed through the skin. The effects of acrylamide are cumulative. Wear gloves and a mask when weighing powdered acrylamide and methylenebisacrylamide. Wear gloves when handling solutions containing these chemicals. Although polyacrylamide is considered to be non-toxic, it should be handled with care because of the possibility that it might contain small quantities of unpolymerized acrylamide.
- Add 600 ml distilled water.
- Heat the solution to 37 C to dissolve the chemicals.
- Make upvolume to 1 liter with distilled water.
<CRITICAL STEP> Cheaper grades of acrylamide and bisacrylamide are often contaminated with metal ions. Stock solutions of acrylamide can easily be purified by stirring overnight with about 0.2 volume of monobed resin (MB-1, Mallinckrodt), followed by filtration through Whatman No. 1 paper.
- Sterilize the solution by filtration through a Nalgene filter (0.45- micron pore size).
- Check that the pH of the acrylamide solution is 7.0 or less.
<STORAGE> Store the solution in dark bottles at room temperature. During storage, acrylamide and bisacrylamide are slowly converted to acrylic acid and bisacrylic acid, so solutions that are older than 1 year should be discarded.