Key features and details
- Sensitivity: 0.25 µg/ml
- Range: 0.313 µg/ml - 5 µg/ml
- Sample type: Plasma, Serum
- Detection method: Colorimetric
- Assay type: Competitive
- Reacts with: Human
Product nameHuman Complement C4 ELISA Kit
See all Complement C4 kits
Intra-assay Sample n Mean SD CV% Overall 3.6% Inter-assay Sample n Mean SD CV% Overall 9.1%
Sample typeSerum, Plasma
Sensitivity= 0.25 µg/ml
Range0.313 µg/ml - 5 µg/ml
Assay time3h 00m
Assay durationMultiple steps standard assay
Species reactivityReacts with: Human
Complement C4 Human in vitro competitive ELISA (Enzyme-Linked Immunosorbent Assay) kit (ab108834) is designed for the quantitative measurement of Complement C4 levels in plasma and serum.
A Complement C4 specific antibody has been precoated onto 96-well plates and blocked. Standards or test samples are added to the wells and subsequently biotinylated Complement C4 is added and then followed by washing with wash buffer. Streptavidin-Peroxidase Complex is added and unbound conjugates are washed away with wash buffer. TMB is then used to visualize Streptavidin-Peroxidase enzymatic reaction. TMB is catalyzed by Streptavidin-Peroxidase to produce a blue color product that changes into yellow after adding acidic stop solution. The density of yellow coloration is inversely proportional to the amount of Complement C4 captured in plate.
Reactivity with C4 cleavage products (C4a, C4b, C4d) has not been determined.
The entire kit may be stored at -20°C for long term storage before reconstitution - Avoid repeated freeze-thaw cycles.
Storage instructionsStore at -20°C. Please refer to protocols.
Components 1 x 96 tests 100X Streptavidin-Peroxidase Conjugate 1 x 80µl 10X Diluent N Concentrate 1 x 30ml 1X Biotinylated Human Complement C4 (Lyophilized) 1 vial 20X Wash Buffer Concentrate 1 x 30ml Chromogen Substrate 1 x 8ml Complement C4 Microplate (12 x 8 well strips) 1 unit Complement C4 Standard 1 vial Sealing Tapes 3 units Stop Solution 1 x 12ml
FunctionNon-enzymatic component of C3 and C5 convertases and thus essential for the propagation of the classical complement pathway. Covalently binds to immunoglobulins and immune complexes and enhances the solubilization of immune aggregates and the clearance of IC through CR1 on erythrocytes. C4A isotype is responsible for effective binding to form amide bonds with immune aggregates or protein antigens, while C4B isotype catalyzes the transacylation of the thioester carbonyl group to form ester bonds with carbohydrate antigens.
Derived from proteolytic degradation of complement C4, C4a anaphylatoxin is a mediator of local inflammatory process. It induces the contraction of smooth muscle, increases vascular permeability and causes histamine release from mast cells and basophilic leukocytes.
Tissue specificityComplement component C4 is expressed at highest levels in the liver, at moderate levels in the adrenal cortex, adrenal medulla, thyroid gland,and the kidney, and at lowest levels in the heart, ovary, small intestine, thymus, pancreas and spleen. The extra-hepatic sites of expression may be important for the local protection and inflammatory response.
Involvement in diseaseComplement component 4A deficiency
Systemic lupus erythematosus
Sequence similaritiesContains 1 anaphylatoxin-like domain.
Contains 1 NTR domain.
modificationsPrior to secretion, the single-chain precursor is enzymatically cleaved to yield non-identical chains alpha, beta and gamma. During activation, the alpha chain is cleaved by C1 into C4a and C4b, and C4b stays linked to the beta and gamma chains. Further degradation of C4b by C1 into the inactive fragments C4c and C4d blocks the generation of C3 convertase. The proteolytic cleavages often are incomplete so that many structural forms can be found in plasma.
N- and O-glycosylated. O-glycosylated with a core 1 or possibly core 8 glycan.
- Information by UniProt
- Acidic complement C4
- Basic complement C4
- C3 and PZP like alpha 2 macroglobulin domain containing protein 2
ab108824 has been referenced in 4 publications.
- Qu S et al. MicroRNA-194 reduces inflammatory response and human dermal microvascular endothelial cells permeability through suppression of TGF-ß/SMAD pathway by inhibiting THBS1 in chronic idiopathic urticaria. J Cell Biochem 121:111-124 (2020). PubMed: 31190349
- Walss-Bass C et al. X-Aptamer Technology Identifies C4A and ApoB in Blood as Potential Markers for Schizophrenia. Mol Neuropsychiatry 5:52-59 (2019). PubMed: 31019918
- Liu Y et al. Toll-like receptor-9 is involved in the development of B cell stimulating factor-induced systemic lupus erythematosus. Exp Ther Med 15:585-591 (2018). PubMed: 29387207
- Owsley C et al. Associations between abnormal rod-mediated dark adaptation and health and functioning in older adults with normal macular health. Invest Ophthalmol Vis Sci 55:4776-89 (2014). ELISA ; Human . PubMed: 24854857