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 porcine 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.
The apolipoproteins are a structurally-unrelated group of proteins that have some association with the transport of lipids in blood. Apolipoproteins, plus phospholipids, cholesterol and triglycerides, form spherical particles with a lipid/hydrophobic center and a (apolipo)protein coat. The apolipoprotein coat promotes aqueous solubility and serves as a ligand for lipoprotein receptors. HDL may contain apolipoproteins A, C, D, E, J, L and M, while LDL contains apolipoproteins B and E.
ApoAI and ApoA2 are major protein components of serum high-density lipoprotein (HDL) and are produced by the liver and small intestine. They are involved in reverse cholesterol transport from tissues to the liver. Polymorphisms of ApoA2 are associated with disorders of cholesterol and fatty acid metabolism. Human ApoB (Apolipoprotein B-100) is a 550 kDa, secreted, palmitoylated glycoprotein that is part of LDL and VLDL particles. It is made by liver and is 4536 aa in length. It binds LDL to the ApoB/E receptor. ApoC activates lipoprotein lipase and may self-associate to form amyloid-type fibrils.
ApoE is a 34 kDa protein component of serum chylomicrons, VLDL, and HDL particles. It mediates the binding, uptake, and catabolism of these particles through interactions with the ApoE receptor and LDL receptors in the liver and brain. ApoE is important in fatty acid homeostasis and memory formation. Polymorphisms encode three variants (ApoE2, 3, 4) which are differentially related to the development of atherosclerosis and neurogenerative disorders, particularly Alzheimer's disease.
Serum amyloid A proteins (SAAs) are a family of homologous apolipoproteins of high density lipoprotein (HDL). They can be divided into two groups. The first group consists of the acute phase SAA1 and SAA2 that associate with HDL during inflammation and remodel the HDL particle by displacing apolipoprotein A1. The second group consists of constitutively expressed SAA4 and SAA5 that exist as minor apolipoproteins on HDL but make up more than 90% of the total SAA during homeostasis.
