Streptavidin and Neutravidin Surfaces

for non-covalent oriented coupling of Biotin modified biochemical species

Avidin is a glycoprotein comprised of four polypeptides that are connected with carbohydrates via glycosidic bonds. Avidin is a tetrameric protein which forms a highly specific binding site for Biotin. Neutravidin is a deglycosylated form of avidin.

The Avidin (Streptavidin/Neutravidin) -Biotin-bond is one of the strongest known, non-covalent bond in biology/ biochemistry (KD= 10-15 mol/l*). The binding site for Biotin is formed by various amino acids (see adjacent figure: binding site). When using covalently attached Avidin, Streptavidin or Neutravidin the molecules are less susceptible for desorption in the presence of alkaline, acids, in solutions of high ionic strength or at high temperatures. Biotin affine proteins can be distinguished by their isoelectric point, specificity and nonspecific binding as illustrated in the following table.

  Avidin         Streptavidin         Neutravidin        
Molecular Weight 67 kDa 53 kDa 60 kDa
Biotin Binding Sites 4 4 4
Isoelectric Point (pl) 10 6.8-7.5 6.3
Specificity Low High Highest
Affinity for Biotin (Kd)     10-15 M 10-15 M 10-15 M
Nonspecific Binding High Low Lowest


PolyAn equips glass slides, coverslips and polymer slides as well as 96-well plates with Streptavidin and Neutravidin surfaces.

Please do not hesitate to contact us, if you would like to functionalize a different format or substrate with our Streptavidin or Neutravidin surfaces.