FAQ: How can I remove imidazole from a protein sample?

 Imidazole does not typically interfere with downstream applications and therefore removal is optional. However, imidazole does absorb UV at 280 nm which can lead to inaccurate protein quantitation.  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.