Data sheets | SPR Sensor chips

NeutrAvidin–modified sensor chips

XanTec NeutrAvidin-modified sensor chips are coated with a bioinert, charge-reduced (poly)carboxylate matrix (HLC), pre-functionalized with a recombinant 52 kDa NeutrAvidin tetramer. This immobilized NeutrAvidin efficiently captures biotinylated biomolecules—including proteins, nucleic acids, peptides, and other biotin-tagged ligands—under physiological conditions.

NeutrAvidin-modified sensor chips are especially tailored to reduce nonspecific binding in SPR assays. This is achieved by combining the deglycosylated, nearly charge-neutral (under physiological conditions) NeutrAvidin, with the highly bioinert, charge-reduced HLC coating, where most negative charges are neutralized. This unique combination renders the NAHLC sensor chips particularly suitable for assessing demanding analytes with high positive net charge.

Due to the exceptionally high binding affinity of NeutrAvidin for biotin (dissociation equilibrium constant ≈ 10⁻¹⁵ M), XanTec’s NAHLC sensor chips allow stable immobilization of biotinylated ligands with negligible dissociation.

Key features:

Reduced nonspecific binding: NAHLC is an alternative to streptavidin-modified sensor chips in assays affected by nonspecific binding.
Fast assay development: No preconcentration or surface activation required. Controlled ligand immobilization is performed under physiological conditions, reducing preparation time and ensuring reproducibility.
Exceptional stability: Exceptionally strong NeutrAvidin-biotin binding makes this surface compatible with most common regeneration protocols.
Oriented immobilization: Controlled biotinylation via biomolecular tools such as AviTag allows for maximum ligand activity and reproducible immobilization results.
Broad application range: Ideal for immobilization of a wide variety of biotinylated ligands, making it suitable for protein interaction studies, nucleic acid hybridization, antibody screening, and other biosensing applications.
Versatile capture capacity: Available on various HLC base coatings, offering different capture capacities to match specific experimental needs.

Schematic illustration of a 3D NAHLC sensor chip. Red and grey dots represent negatively charged carboxyl groups and charge-neutral hydroxyl groups distributed along the green polymer chains. The decaying red gradient represents the evanescent field. The magnified view shows immobilized NeutrAvidin (dark blue) binding a biotinylated protein ligand (yellow).¹

Product code	NAHCP²	NAHLC30M	NAHLC200M	NAHLC1500M
Base coating	2D, ultra-short bioinert polycarboxylate (medium density)	3D, 30 nm bioinert polycarboxylate (medium density, reduced charge)	3D, 200 nm bioinert polycarboxylate (medium density, reduced charge)	3D, 1500 nm bioinert polycarboxylate (medium density, reduced charge)
Capture immobilization capacity [µRIU]³	≈ 800	≈ 1,700	≈ 3,300	≈ 4,000
Recommended ligands	biotinylated proteins peptides nucleic acids carbohydrates
Recommended analytes	proteins peptides nucleic acids carbohydrates viruses and cells	proteins peptides nucleic acids carbohydrates	peptides nucleic acids carbohydrates	peptides nucleic acids carbohydrates small molecules
Intended purpose	kinetics of medium and large analytes especially suitable for weak binders with fast on- and off-rates including carbohydrates capture immobilization of biotinylated secondary antibodies reduction of nonspecific binding	kinetics of medium and large analytes especially suitable for weak binders with fast on- and off-rates including carbohydrates capture immobilization of biotinylated secondary antibodies reduction of nonspecific binding	all-purpose kinetics of medium analytes including carbohydrates especially suitable for situations requiring higher capture densities reduction of nonspecific binding	kinetics of medium and small analytes including carbohydrates especially suitable for situations requiring higher capture densities reduction of nonspecific binding

¹ All illustrations are schematic representations and are not drawn to scale; dimensions, densities, and spatial relationships do not reflect actual physical or chemical proportions.

² NAHCP is the only variant that employs the classic HC matrix instead of HLC.

³ Based on specific binding of 100 µg/mL biotinylated bovine serum albumin (BSA) in phosphate-buffered saline (PBS), with 1 µRIU corresponding approximately to 1 RU.



Products | SPR Sensor chips | Data sheets

NeutrAvidin–modified sensor chips