Pentraxins are a superfamily of acute phase reactants charactarized by a pentameric
structure. The C-reactive protein (CRP) and serum amyloid P-component (SAP) are wellcharactarized
short Pentraxins, which are produced in the liver in response to inflammatory
mediators. Pentraxin 3 (PTX3), also known as Tumor necrosis factor-Stimulated Gene 14
(TSG-14), is the prototypic long Pentraxin, with a high degree of conservation from mouse to
Human PTX3 encodes a 45 kDa secretory glycoprotein with a 162 amino acid N-terminal
extension and a 202 amino acid C-terminal Pentraxin domain. The protein is locally produced
and released by a variety of cell types including macrophages, neutrophils, myeloid-derived
mesangial cells, synovial cells, smooth muscle cells, alveolar epithelium, and glial cells.
PTX3 is induced in response to either inflammatory cytokines interleukin-1 β (IL-1 β) and
tumor necrosis factor α (TNFα) or the selected associated molecular patterns (PAMPs).
PTX3 has a dual role in the regulation of the innate immune response. Via its C-terminal
Pentraxin domain, immobilized PTX3 will bind complement component C1q to induce
classical complement activation. However, fluid-phase PTX3 inhibits classical complement
activation. Furthermore PTX3 participates in the clearance of apoptic cells.
PTX3 is elevated in critically ill patients, with a gradient from systematic inflammatory
resonse syndrome to septic shock, and in several other diseases, such as mycocardial
infarction, rheumatoid arthritis, atherosclerosis, small vessel vasculitis and psoriasis.
Furthermore serum levels of PTX3 are higher in preeclamsia compared with normal
The human Pentraxin 3 ELISA kit is to be used for the in vitro quantitative determination of human Pentraxin 3 in plasma samples and cell culture supernatant.
The human pentraxin 3 ELISA is a ready-to-use solid-phase enzyme-linked immunosorbent assay based on the sandwich principle with a working time of 3½ hours.
The efficient format of 2 plates with twelve disposable 8-well strips allows free choice of batch size for the assay.
Samples and standards are captured by a solid bound specific antibody.
Biotinylated tracer antibody will bind to captured human pentraxin 3.
Streptavidin-peroxidase conjugate will bind to the biotinylated tracer antibody.
Streptavidin-peroxidase conjugate will react with the substrate, tetramethylbenzidine (TMB).
The enzyme reaction is stopped by the addition of oxalic acid.
The absorbance at 450 nm is measured with a spectrophotometer. A standard curve is obtained by plotting the absorbance (linear) versus the corresponding concentrations of the human pentraxin 3 standards (log).
The human pentraxin 3 concentration of samples, which are run concurrently with the standards, can be determined from the standard curve.
The linearity of the assay was determined by serially diluting a sample containing 2353 pg/ml human pentraxin 3. The diluted samples were measured in the assay. The line obtained a slope of 1.005 and a correlation coefficient of 1.000.