Detection principle:

Double antibody sandwich ELISA was used in this experiment. Anti-human IL-12/IL-23p40 monoclonal antibody is coated on a microplate, and IL-12/IL-23p40 in samples and standards will bind to the antibody immobilized on the plate, and the free components will be washed away; Horseradish peroxidase-labeled anti-human IL-12/IL-23 p40 polyantibody was added and unbound antibody was washed away; Adding a substrate solution (chromogenic agent), the color of the solution is proportional to the bound target protein; A stop solution was added to stop the reaction, and the absorbance value was measured at a wavelength of 450 nm (reference calibration wavelength of 540 nm or 570 nm).

Test Type:Double antibody sandwich method

Form:Pre-coated 96-well plate

Test Sample Type:Cell supernatant, serum, plasma

Sample Load:100ul

Kit Components:

A copy of the pre-coated 96-well plate, standard, anti-human IL-12/IL-23 p40 detection antibody, buffer for dilution, chromogenic solution (A, B), wash solution, stop solution, SA-HRP, plate sealing membrane, and instructions.

Sensitivity:3.5 pg/mL

Detection range:62.5-4,000 pg/mL

Recovery Range:89-114%

Save Method:2-8℃

Standard curve plot

Background:

IL-12, also known as natural killer cell stimulating factor (NKSF) or cytotoxic lymphocyte maturation factor (CLMF), is a pleiotropic cytokine mainly produced by antigen-presenting cells (monocytes/macrophages, dendritic cells, and B lymphocytes). IL-12 has a variety of effects on T lymphocytes and natural killer (NK) cells, including the ability to stimulate cytotoxicity, proliferation, cytokine production, and Th1 subset development.

IL-12 is a 70 kDa (p70) heterodimeric glycoprotein linked by disulfide bonds, consisting of a 40 kDa (p40) subunit and a 35 kDa (p35) subunit. The p40 and p35 subbases do not possess IL-12 activity in themselves, but homodimers of p40 have been shown to bind IL-12 receptors and are IL-12 antagonists.

The genes of human p40 and p35 located on chromosomes 5 and 3, respectively, are independently regulated. The expression of p35 mRNA has been found to be almost ubiquitous, however, the p35 subunit was not detected in the culture supernatant of cells expressing p35 or p35 and p40 mRNA only. The p40 mRNA expression level was higher in cells expressing both p35 and p40 mRNA, and together with the heterodimeric IL-12 p70, a free p40 subunit unrelated to the p35 subunit was secreted. Most of the free p40 subunits secreted by the various human cell lines examined have been found to exist in monomeric form. The content of free p40 far exceeds p70 in the supernatants of various activated human monocytes, and the levels of p70 measured by bioassays are consistent with those measured using p70-specific immunoassays, suggesting that p40 monomers are not potent IL-12 antagonists. Currently, the physiological role of the free p40 subunit is unclear.