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Complement factor D ELISA kit [Human]-1 x 96 det. (CAT#: CB-P089-K) Datasheet

Product Type
The alternative pathway of complement represents an important body fluid component that naturally defends against microbial attack. The interaction of protein C3, factor B and factor D leads to the formation of alternative C3- and C5-convertases, namely C3bBb and C3bBbC3b(n). These multi-component enzymes assemble on the surface of the alternative pathway of complement activators and are stabilized by properdin (P). The participation of alternative pathways of complement has been involved in the pathogenesis of many human diseases. Factor D is a 24 kD serine protease that replaces the complement pathway and is synthesized as a precursor single-chain molecule. Factor D is unique among serine proteases because it does not require enzyme cleavage to express proteolytic activity, nor does it require activation of serine protease inhibitors to control it. Factor D is highly specific and cleaves factor B that binds to C3b, thereby generating C3bBb enzyme. Factor D is the rate-linked C3 convertase of the alternative pathway. In addition, the role of factor D in adipose tissue is different from its role as a complement protein. The normal value in human EDTA plasma is 1.05 (±0.27) μg/ml. In healthy individuals, factor D is rapidly eliminated by the kidneys, and changes in renal insufficiency and changes in synthesis did not lead to increased levels of factor D in patients with renal failure. The level of patients with chronic renal failure (CRF) increased to 4.35 (±3.03) μg/ml, while the level of patients with end-stage renal disease (ERDS) increased to 12.1 (±3.53) μg/ml. A measurable factor D content (0.62±0.33 ng/ml) was detected in the urine of 85% of healthy individuals. The concentration of factor D in the urine of patients with tubular proteinuria increased to 230 (±313) ng/ml.
The human complement factor D ELISA kit is used for the in vitro quantitative determination of human complement factor D in serum, plasma and urine samples.
Human complement factor D ELISA kit is a ready-to-use solid-phase enzyme-linked immunosorbent assay based on the sandwich principle. The working time is 3 hours. The effective format of two plates with twelve disposable 8-well strips allows free choice of batch size for determination. Samples and standards are incubated in microtiter wells coated with antibodies that recognize human complement factor D. The biotinylated tracer antibody will bind to the captured human complement factor D. The streptavidin-peroxidase conjugate will bind to the biotinylated tracer antibody. The streptavidin-peroxidase conjugate will react with the substrate tetramethylbenzidine (TMB). The enzyme reaction is stopped by adding oxalic acid. Measure the absorbance at 450nm with a spectrophotometer. Draw a standard curve by plotting the absorbance (linear) relative to the corresponding concentration (logarithm) of the human complement factor D standard. The concentration of human complement factor D in the sample run at the same time as the standard can be determined from the standard curve.
1 x 96 det.
Detection Method
Enzyme immunoassay (ELISA) technique
Detection Limit
1.8 to 20 ng/ml
1.8 ng/ml
Serum, plasma, tissue homogenates, cell lysates, cell culture supernates and other biological fluids
Specimen Collection
Blood samples were collected using sterile venipuncture techniques, and serum was obtained using standard procedures. At least 5 ml of whole blood is recommended. Let the blood clot in the serum test tube for 60-65 minutes at room temperature (20-25°C). Centrifuge the blood sample and transfer the cell-free serum to a clean test tube. The serum must be handled correctly to prevent complement activation in vitro. Serum should be frozen in a sealed tube at -70°C or lower for long-term storage or transport on dry ice. The sample should not be frozen and thawed more than once. Do not use jaundice, lipemia and hemolytic serum. You cannot use heat-inactivated serum. Plasma cannot be used.
Sample Volume
100 µl/well
Species Reactivity
Cross Reactivity
Horse - Weak, Mouse - No, Rabbit - No, Swine - Weak
Protocol Length
2 hours
Product should be stored at 4 °C. Under recommended storage conditions, product is stable for at least six months.
Research Use
For research use only. Not for use in or on humans or animals or for diagnostics. It is the responsibility of the user to comply with all local/state and Federal rules in the use of this product. Hycult Biotech is not responsible for any patent infringements that might result with the use of or derivation of this product.

All products and services are for Research Use Only. Do Not use in humans.


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