本试剂盒应用双抗体夹心酶标免疫分析法测定标本中anti-oxLDL Ab水平。用纯化的oxLDL抗原包被微孔板，制成固相抗体，往包被单抗的微孔中依次加入anti-oxLDL Ab、生物素化的oxLDL、HRP标记的亲和素，经过彻底洗涤后用底物TMB显色。TMB在过氧化物酶的催化下转化成蓝色，并在酸的作用下转化成最终的黄色。颜色的深浅和样品中的anti-oxLDL Ab呈正相关。用酶标仪在450nm波长下测定吸光度（OD值），计算样品浓度。
Intended use
This immunoassay kit allows for the specific measurement of rabbit Anti-oxLDL Ab concentrations in serum and plasma.
Introduction
Anti-oxLDL antibodies are associated with clinical conditions like atherosclerosis, carotid stenosis and other coronary artery dysfunction. Anti-ox-LDL antibodies may be important in other diseases like diabetes hypertension and endometriosis1. Hypercholesterolemia is closely associated with increased risk of atherosclerosis. The cholesterol accumulated in the atherosclerotic plaque is derived primarily from low-density lipoprotein (LDL). Oxidation of LDL is now accepted as a critical event in the atherogenic process. Free radicals like superoxide and nitric oxide (-O2, NO) generated in biological reactions in the body contribute to the oxidation of LDL. The NO radical has been shown to oxidize apolipoprotein B a constituant of LDL. Similarly, lipoxygenases and oxidants like peroxynitrite can oxidize the lipid moieties in LDL. It has been demonstrated that oxLDL and not native LDL is taken up by scavenger receptors on monocytes, smooth muscle cells and macrophages in the blood vessels. The oxidation of LDL increases the affinity of oxLDL to acetyl receptors of macrophages. As this pathway of oxLDL uptake is unregulated, it results in the formation of lipid-laden macrophages (foam cells). The presence of foam cells is the earliest step in the formation of atherosclerotic plaque in blood vessels. Later, other inflammatory molecules released by leukocytes promote the progression of atherosclerotic plaque.
Test principle
Microwells are coated with purified native LDL or oxLDL antigen. The unreacted sites on both type of strips (LDL or oxLDL) are blocked to reduce nonspecific binding. Controls, calibrators and serum samples are incubated in the antigen coated wells to allow specific anti-oxLDL ntibodies present in the serum to bind. Unbound antibody and other serum proteins are removed by washing the microwells. Bound antibodies are detected by adding an enzyme labeled anti-rabbit IgG conjugate to the wells. Unbound conjugate is removed by washing. Specific enzyme substrate (pNPP) is then added to the wells and the presence of antibodies is detected by a color change produced by the conversion of pNPP substrate to a yellow reaction product. The reaction is stopped and the intensity of the color change, which is proportional to the concentration of antibody, is read as absorbance by a spectrophotometer at 405 nm. Each specimen is run on LDL and oxLDL wells. Absorbance value on native-LDL is subtracted from the absorbance obtained on oxLDL for controls, calibrators and specimens. The concentration of anti-oxLDL is determined from the calibration curve. Results are expressed in Enzyme Units per milliliter (EU/ml).
