NeutrAvidin
NeutrAvidin protein is a deglycosylated version of avidin, with a mass of approximately 60,000 daltons. As a result of carbohydrate removal, lectin binding is reduced to undetectable levels, yet biotin binding affinity is retained because the carbohydrate is not necessary for this activity. Avidin has a high pI but NeutrAvidin has a near-neutral pI (pH 6.3), minimizing non-specific interactions with the negatively charged cell surface or with DNA/RNA. Neutravidin still has lysine residues that remain available for derivatization or conjugation.