Bio-Rad Nuvia™ IMAC Resin - Manual (Page 37)

Nuvia IMAC Ni-Charged Resin 33
Problem Possible Cause Solution
Histidine-tagged
protein is not pure
(continued from
previous page) Association between
the histidine-tagged
protein and protein
contaminant
Potential degradation
of fusion protein by
proteases
Contaminants exhibit
similar affinity to target
protein
Add nonionic detergent or alcohol (that
is, ≤2% Triton X-100, 2% Tween 20, or
≤20% glycerol) to reduce hydrophobic
interactions. Concentration of NaCl may
be increased to minimize electrostatic
interactions
Include 1 mM PMSF or other protease
inhibitor in lysis buffer to reduce partial
degradation
Add a chromatography step; that is, ion
exchange, hydrophobic interaction, or
size exclusion