Natural and recombinant human CD23. This assay recognizes the 25 kDa fragment (aa 150-321) and the full length extracellular domain (aa 48-321) of human CD23/Fc epsilon RII.
< 0.5% cross-reactivity observed with available related molecules.Cross-species reactivity not tested.
No significant interference observed with available related molecules.
The Quantikine Human CD23 immunoassay is a 4.5 hour solid phase ELISA designed to measure human soluble CD23 in cell culture supernates, serum, plasma, and urine. It contains NS0-expressed recombinant human CD23 (extracellular domain) and has been shown to accurately quantitate the recombinant factor. Results obtained using natural human CD23 showed linear curves that were parallel to the standard curves obtained using the Quantikine kit standards. These results indicate that this kit can be used to determine relative mass values for naturally occurring soluble CD23.
Intra-Assay Precision (Precision within an assay) Three samples of known concentration were tested on one plate to assess intra-assay precision.
Inter-Assay Precision (Precision between assays) Three samples of known concentration were tested in separate assays to assess inter-assay precision.
The recovery of CD23 spiked to levels throughout the range of the assay in various matrices was evaluated.
Average % Recovery
Cell Culture Media (n=4)
EDTA Plasma (n=4)
Heparin Plasma (n=4)
To assess the linearity of the assay, samples containing high concentrations of CD23 were serially diluted with Calibrator Diluent to produce samples with values within the dynamic range of the assay.
Preparation and Storage
Store the unopened product at 2 - 8 °C. Do not use past expiration date.
Background: CD23/Fc epsilon RII
CD23, also known as Fc epsilon RII, is a type 2 transmembrane C-type lectin that binds IgE, CD21, CD11b and CD11c. It is expressed on a variety of hematopoietic cells and functions in allergic immune responses.
Fc epsilon Receptor II
Entrez Gene IDs
2208 (Human); 14128 (Mouse); 171075 (Rat);
BLAST-2; CD23; CD23A; CD23CD23 antigen; CLEC4J; CLEC4JC-type lectin domain family 4 member J; C-type lectin domain family 4, member J; Fc epsilon RII; Fc fragment of IgE, low affinity II, receptor for (CD23); FCE2Fc fragment of IgE, low affinity II, receptor for (CD23A); fc-epsilon-RII; FCER2; Fcer2a; FceRII; IGEBF; Immunoglobulin E-binding factor; low affinity immunoglobulin epsilon Fc receptor; Ly-42; Lymphocyte IgE receptor;