Human IgA ELISA Kit

Human IgA ELISA Kit (ab196263) is a single-wash 90 min sandwich ELISA designed for the quantitative measurement of IgA protein in cell culture supernatant, milk, saliva, serum, urine, and plasma. It uses our proprietary SimpleStep ELISA® technology. Quantitate Human IgA with 0.25 ng/ml sensitivity.

SimpleStep ELISA® technology employs capture antibodies conjugated to an affinity tag that is recognized by the monoclonal antibody used to coat our SimpleStep ELISA® plates. This approach to sandwich ELISA allows the formation of the antibody-analyte sandwich complex in a single step, significantly reducing assay time. See the SimpleStep ELISA® protocol summary in the image section for further details. Our SimpleStep ELISA® technology provides several benefits:

- Single-wash protocol reduces assay time to 90 minutes or less
- High sensitivity, specificity and reproducibility from superior antibodies
- Fully validated in biological samples
- 96-wells plate breakable into 12 x 8 wells strips

A 384-well SimpleStep ELISA® microplate (ab203359) is available to use as an alternative to the 96-well microplate provided with SimpleStep ELISA® kits.

ASSAY SPECIFICITY

This kit recognizes both native and purified Human IgA protein in serum, plasma, milk, urine, saliva, and cell culture media samples only.

Cell and tissue extracts have not been tested with this kit.

CROSS REACTIVITY

Human IgG, human IgM, and human IgE were prepared at 20 ng/mL and 10 ng/mL in Sample Diluent NS and assayed for cross reactivity. No significant cross reactivity was observed for human IgG, human IgM, or human IgE at either concentration with a mean OD deviation from background of 0.006.

INTERFERENCE

Purified human IgA was assayed at 20 ng/mL in the presence and absence of 20 ng/mL of human IgM or human IgE to determine interference. After background subtraction, human IgM and IgE were found to interfere with the assay by 9.24%. Human IgA was assayed at 20 ng/mL in the presence and absence of 80 ng/mL of human IgG to determine interference. After background subtraction, no significant interference was observed.

SPECIES REACTIVITY

This kit recognizes human IgA protein.

Other species reactivity was determined by measuring 1:200,000 (dilution) serum samples of various species, interpolating the protein concentrations from the human standard curve, and expressing the interpolated concentrations as a percentage of the protein concentration in human serum assayed at the same dilution.

Reactivity < 3% was determined for the following species: Mouse, Rat, Hamster, Guinea Pig, Rabbit, Dog, Goat, Pig, Cow

CALIBRATION

This immunoassy is calibrated against a highly purified human IgA. The NIBSC/WHO unclassified purified human IgG/IgM/IgG preperation 67/086. was evaluatied in this kit.

The dose response curve of the unclassified standard parallels the SimpleStep standard curve. To Convert sample values obtained with the SimpleStep IgA kit to approximate NIBSC International units, use the equation below.

NIBSC 67/086 approximate value (IU/mL) = 0.000064 (6.4e-5 IU) x SimpleStep IgA value (ng/mL)

Human Immunoglobulin A (IgA) belongs to the immunoglobulin family of proteins which include Human IgG, IgE, and IgM, and are known as antibodies. IgA has an essential role in mucosal immunity. IgA is the second most common serum Ig and is about one-fifth of the concentration of IgG, however it is the most abundant immunoglobulin in secretions, such as saliva, mucus, sweat, and tears. In normal human serum, IgA is found mainly as a monomeric, alternatively, in secretions, IgA is found as a dimer containing two additional proteins, secretory piece, and a J chain. The secretory piece is synthesized in the epithelial cells and is added to IgA as it passes into the secretions, protecting it from degradation. IgA works is with lysozymes to hydrolyze carbohydrates in bacterial cells walls to clear the infection. The most common disease associated with high levels of IgA in the kidney is IgA nephropathy, aka Berger’s disease. There is no clear clarification as to why IgA deposits occur in the kidney, however abnormality in the immune system is a possibility. Other diseases that IgA is associated with are Celiac disease and Henoch-Schonlein purpura (HSP).