Imidazole does not typically interfere with downstream applications and therefore removal is optional. Boiling a sample containing imidazole prior to SDS–PAGE may cause acid-labile bonds to hydrolyze. It is instead recommended to incubate the sample at 70°C for 5 min in SDS loading buffer prior to analysis. If it is necessary to eliminate the imidazole, it can be removed by dialysis, ammonium sulfate precipitation, ultrafiltration or by using a size-exclusion desalting column.