What is metal ion transfer?
What is metal ion transfer?
Intermediate metal ions (such as Cu2+, Ni2+, and Co2+) will bind to thiol groups. Dithiothreitol (DTT) can extract the metal ion from the resin, which is referred to as metal ion transfer. This also happens at high beta-mercaptoethanol (BME) concentrations. When this occurs, the resin will turn brown and may elute a brown precipitate in the flowthrough or washes. However, Takara Bio's studies have shown that at low concentrations of DTT (<1 mM) or BME (<10 mM), the his-tagged protein in the elution fractions is not affected by the metal ion transfer even though the resin may be slightly discolored.