Neopterin, Human, BioAssay(TM) ELISA Kit

Catalog Number: USB-N1060-49
Article Name: Neopterin, Human, BioAssay(TM) ELISA Kit
Biozol Catalog Number: USB-N1060-49
Supplier Catalog Number: N1060-49
Alternative Catalog Number: USB-N1060-49-96
Manufacturer: US Biological
Category: Kits/Assays
Neopterin [D-erythro-neopterin] belongs to the group of pteridines. Neopterin as well as other pteridines are derived in vivo from guanosine-triphophate (GTP). Neopterin represents a precursor molecule of biopterin that is an essential cofactor in neurotransmitter synthesis, and it is also involved in variety of oxidation-reduction reactions in the body. The enzyme GTP-cyclohydrolase-I catalyzes this reaction in monocytes and macrophages. Neopterin is exclusively released by activated macrophages, and can be determined in serum, plasma and other body fluids. Neopterin biosynthesis is closely associated with activation of the cellular immune system. Higher levels of neopterin were found in patients with viral infections. Antigenic stimulation of human peripheral blood mononuclear cells leads to neopterin release into cell culture medium. Gamma Interferon treatment of macrophages in vitro also increases neopterin levels and generates highly reactive oxygen species (ROS). Neopterin is capable of enhancing ONOO- - as well as Cu(II)-mediated LDL oxidation, whereas 7,8-dihydroneopterin mainly protects LDL from oxidation. Changes in neopterin concentrations in serum or urine can predict complications such as graft rejection in organ transplant recipients. Elevated neopterin levels are found in autoimmune disorders such as rheumatoid arthritis and systemic lupus erythematosus (SLE). Neopterin levels can be used as prognostic predictors for certain types of malignancies. Measurement of neopterin levels has particular value for monitoring patients infected with HIV. Neopterin is eliminated primarily in the urine, so evaluation of urinary neopterin levels may be useful in assessing activation of the cellular immunity system even in the absence of typical clinical symptoms, since a correlation has been observed with the course of diseases involving cellular immunity activation and urinary levels. Principle of the Test: Neopterin ELISA kit is based on competitive binding of human Neopterin from serum samples and enzyme-labeled Neopterin to Neopterin specific antibodies immobilized on microtiter plates. After a washing step, chromogenic substrate is added and color developed. The enzymatic reaction (blue color is inversely proportional to the amount of Neopterin present in the sample. The reaction is terminated by adding stopping solution (converts blue to yellow. Absorbance is then measured on an ELISA reader at 450nm and the concentration of Neopterin in samples and control is read off the standard curve. Range: Intra-assay Precision CV: < 10% for Neopterin range 2-50nmol/L Inter-assay Precision CV: < 10% for Neopterin range 2-50nmol/L Sensitivity: 0.7nmol/L Kit Components: N1060-49A: Micrototer Plate, 1x96 wells N1060-49B: Standard 0nM, 1x1.5ml N1060-49C: Standard 1.35nM, 1x1.5ml N1060-49D: Standard 4nM, 1x1.5ml N1060-49E: Standard 12nM, 1x1.5ml N1060-49F: Standard 37nM, 1x1.5ml N1060-49G: Standard 111nM, 1x1.5ml N1060-49H: Assay Buffer, 1x21ml N1060-49J: Control 1, 4-8.3nM, 1x1.5ml N1060-49K: Control 2, 15.2-282nM, 1x1.5ml N1060-49L: Neopterin (HRP Conjugate, 1x13ml N1060-49M: Neopterin Antibody, 1x5ml N1060-49N: Wash Buffer, 20X, 1x50ml N1060-49P: TMB Substrate Solution, 1x19ml N1060-49Q: Stop Solution, 1N H2SO4, 1x19ml Storage and Stability: Store components at 4C. Stable for 6 months after receipt. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.