INTENDED USE & DESCRIPTION
For use as quantitative controls for the determination of cytokine concentrations in biological fluids. Concentrations have been assigned using R&D Systems’ Quantikine® kits. Controls are prepared in diluted serum with preservatives. They contain recombinant human cytokines at low, medium and high concentrations. Controls are supplied lyophilized.
STORAGE & STABILITY
Unreconstituted Controls should be stored at 2-8 °C and are stable for at least 6 months from date of receipt. Depending on the analyte of interest, reconstituted controls may be stable when stored at
REAGENT PREPARATION
Reconstitute each vial with the volume of deionized or distilled water indicated on the product datasheet.
PROCEDURE & EXPECTED VALUES
Controls should be assayed in the same manner as unknown specimens.
The acceptable ranges for the analytes in these controls are printed on the product datasheet. Due to possible variations in techniques and methodologies, it is recommended that each laboratory determine its own target range. Laboratories using other test systems should establish their own acceptable ranges as these assays may produce different values.
TECHNICAL HINTS & LIMITATIONS OF THE PROCEDURE
• The ranges were determined using R&D Systems’ Quantikine kits. If expected values are not obtained, verify that the lot numbers on the vials correspond with the lot numbers listed above and the correct volume of deionized or distilled water was used for reconstitution of the controls.
• The results obtained with these controls depend upon several factors associated with methods and instrumentation. Test systems other than those supplied by R&D Systems may result in values that differ from those printed on this product datasheet.
Myeloperoxidase (MPO) is a heme-containing enzyme belonging to the XPO subfamily of peroxidases. It is an abundant neutrophil and monocyte glycoprotein that catalyzes the hydrogen peroxide dependent formation of hypochlorus acid (HOCl) and other reactive species. Enzymatically active MPO is a disulfide-linked tetramer that contains two heme groups and two copies each of the heavy and light chains. MPO binds Albumin, MMR, Cytokeratin 1 on vascular endothelial cells, HMW Kininogen, and Integrin CD11b/CD18 on neutrophils. These interactions promote MPO clearance, a reduction of nitric oxide and bradykinin levels, reduced vasodilation, and continued neutrophil activation. Neutrophil MPO is stored in cytoplasmic azurophilic granules. Upon cellular activation and degranulation, MPO is delivered into phagosomes where it is required for the killing of phagocytosed bacteria. Activated neutrophils also release granule contents extracellularly. Elevated plasma MPO levels have been associated with a variety of clinical conditions including systemic inflammation, eclampsia, risk of cardiovascular events, vascular endothelial dysfunction, severity of multiple sclerosis, and prospective mortality and oxidative stress during hemodialysis.
