Products | SPR Sensor chips | Data sheets

Protein A–modified sensor chips

XanTec’s Protein A (PA) sensor chips are coated with a bioinert polycarboxylate matrix pre-functionalized with a recombinant 47 kDa Protein A. This non-glycosylated variant contains five IgG-binding domains, providing high-affinity binding to the Fc region of all human IgG1, IgG2, and IgG4 subclasses. It also shows strong affinity for mouse IgG2a, IgG2b, and IgG3, as well as total IgG from cow, goat, sheep, rabbit, and other mammals.

Due to the slightly hydrophobic character of Protein A, some nonspecific binding may occur. The use of blocking agents (e.g., BSA) and/or nonionic detergents (e.g., Tween) in the running buffer is therefore recommended to minimize background signals. XanTec’s PA sensor chips are ready-to-use, eliminating time-intensive assay optimization and streamlining workflows.

Key features:

Schematic illustration of a 3D PA sensor chip. Red dots represent negatively charged carboxyl groups along the green polymer chains. The magnified view shows Protein A (orange) binding to the Fc region of an antibody (blue).1
Product code PAP PAD200L PAHC30M PAHC200M
Base coating 2D, ultra-short bioinert CM-dextran
(high density)		 3D, 200 nm bioinert CM-dextran
(low density)		 3D, 30 nm bioinert polycarboxylate
(medium density)		 3D, 200 nm bioinert polycarboxylate
(medium density)
Capture immobilization capacity [µRIU]3 ≈ 5,000 ≈ 12,000 ≈ 6,000 ≈ 11,000
Ligands Fc region of human IgG1, IgG2, and IgG4; strong affinity for mouse IgG2a, IgG2b, IgG3, and total IgG from cow, goat, sheep, and rabbit
Recommended analytes
  • proteins
  • peptides
  • nucleic acids
  • proteins
  • peptides
  • nucleic acids
  • small molecules
  • proteins
  • peptides
  • nucleic acids
  • carbohydrates
  • proteins
  • peptides
  • nucleic acids
  • carbohydrates
  • small molecules
Intended purpose
  • kinetic measurements via oriented Fc capture
  • capture of Fc fusion proteins and antibodies for medium- to large-sized analytes
  • antibody quantification
  • analysis of small- to medium-sized analytes
  • antibody quantification
  • analysis of medium- to large-sized analytes including carbohydrates

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 Table includes a selection from XanTec’s full PA sensor chip portfolio.

3 Maximum immobilization capacities are based on capture from a 100 µg/mL solution of Protein A-purified, pooled rabbit IgG in PBS, with 1 µRIU corresponding approximately to 1 RU.