Knight:Deionization

Overview
Deionization is the process of removing all ions from a solution. Solutions of urea, acrylamide, formamide and glyoxal can dissociate over time into ionic species. These ionic species can often be detrimental to proteins, RNA etc.

Materials

 * AG 501-X8(D) resin from Bio-Rad (catalog number 143-6425)
 * A solution to be deionized

Procedure

 * 1) Weigh 5g of resin for every 100mL of formamide or acrylamide solution. Use 1 g of resin per mL of glyoxal.
 * 2) *This amount is sufficient for any concentration.
 * 3) Add resin to solution.
 * 4) *Molecular Cloning suggests washing the resin with 1mL of the solution to be deionized per mL of resin and discard prior to addition of resin to solution.
 * 5) Stir for 1 hour.
 * 6) Check pH to insure deionization is complete. If the resin turns gold, more resin is needed.
 * 7) If deionization is not complete, remove the resin by filtration and add more resin.
 * 8) Remove resin by filtering using a syringe and 0.22&mu;m filter.
 * 9) *Is there an easier/better way?