Human DAF ELISA Kit (CD55) (ab256405)
Key features and details
- One-wash 90 minute protocol
- Sensitivity: 14.27 pg/ml
- Range: 62.5 pg/ml - 4000 pg/ml
- Sample type: Cell culture media, Cell Lysate, Cit plasma, EDTA Plasma, Hep Plasma, Serum
- Detection method: Colorimetric
- Assay type: Sandwich (quantitative)
- Reacts with: Human
Overview
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Product name
Human DAF ELISA Kit (CD55) -
Detection method
Colorimetric -
Precision
Intra-assay Sample n Mean SD CV% Serum 8 3.7% Inter-assay Sample n Mean SD CV% Serum 3 2.3% -
Sample type
Serum, Cell Lysate, Cell culture media, Hep Plasma, EDTA Plasma, Cit plasma -
Assay type
Sandwich (quantitative) -
Sensitivity
14.27 pg/ml -
Range
62.5 pg/ml - 4000 pg/ml -
Recovery
Sample specific recovery Sample type Average % Range Serum 86 80% - 90% Cell culture media 105 94% - 114% Hep Plasma 102 101% - 103% EDTA Plasma 97 96% - 99% Cit plasma 85 82% - 88% -
Assay time
1h 30m -
Assay duration
One step assay -
Species reactivity
Reacts with: Human
Does not react with: Cow -
Product overview
Human DAF ELISA Kit (CD55) (ab256405) is a single-wash 90 min sandwich ELISA designed for the quantitative measurement of DAF (CD55) protein in cell culture media, cell lysate, cit plasma, edta plasma, hep plasma, and serum. It uses our proprietary SimpleStep ELISA® technology. Quantitate Human DAF (CD55) with 14.27 pg/ml sensitivity.
SimpleStep ELISA® technology employs capture antibodies conjugated to an affinity tag that is recognized by the monoclonal antibody used to coat our SimpleStep ELISA® plates. This approach to sandwich ELISA allows the formation of the antibody-analyte sandwich complex in a single step, significantly reducing assay time. See the SimpleStep ELISA® protocol summary in the image section for further details. Our SimpleStep ELISA® technology provides several benefits:
- Single-wash protocol reduces assay time to 90 minutes or less
- High sensitivity, specificity and reproducibility from superior antibodies
- Fully validated in biological samples
- 96-wells plate breakable into 12 x 8 wells stripsA 384-well SimpleStep ELISA® microplate (ab203359) is available to use as an alternative to the 96-well microplate provided with SimpleStep ELISA® kits.
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Notes
Decay-Accelerating Factor (DAF), also known as CD55, is a 70kD membrane protein that regulates the complement system on the cell surface. DAF recognizes C4b and C3b fragments that are created during activation of C4 (classical or lectin pathway) or C3 (alternative pathway). Interaction of DAF with cell-associated C4b of the classical and lectin pathways interferes with the conversion of C2 to C2b, thereby preventing formation of the C4b2b C3-convertase. Interaction of DAF with C3b of the alternative pathway blocks the conversion of factor B to Bb by factor D, thereby preventing formation of the C3bBb C3 convertase of the alternative pathway. By limiting the amplification convertases of the complement cascade, DAF indirectly blocks the formation of the membrane attack complex. DAF shares 47%, 45%, and 56% sequence homology with mouse, rat, and cow respectively.
Abcam has not and does not intend to apply for the REACH Authorisation of customers’ uses of products that contain European Authorisation list (Annex XIV) substances.
It is the responsibility of our customers to check the necessity of application of REACH Authorisation, and any other relevant authorisations, for their intended uses. -
Platform
Pre-coated microplate (12 x 8 well strips)
Properties
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Storage instructions
Store at +4°C. Please refer to protocols. -
Components 1 x 96 tests 10X Human DAF (CD55) Capture Antibody 1 x 600µl 10X Human DAF (CD55) Detector Antibody 1 x 600µl 10X Wash Buffer PT (ab206977) 1 x 20ml 50X Cell Extraction Enhancer Solution (ab193971) 1 x 1ml 5X Cell Extraction Buffer PTR (ab193970) 1 x 10ml Antibody Diluent 4BI 1 x 6ml Human DAF (CD55) Lyophilized Recombinant Protein 2 vials Plate Seals 1 unit Sample Diluent NS (ab193972) 1 x 50ml SimpleStep Pre-Coated 96-Well Microplate (ab206978) 1 unit Stop Solution 1 x 12ml TMB Development Solution 1 x 12ml -
Research areas
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Function
This protein recognizes C4b and C3b fragments that condense with cell-surface hydroxyl or amino groups when nascent C4b and C3b are locally generated during C4 and c3 activation. Interaction of daf with cell-associated C4b and C3b polypeptides interferes with their ability to catalyze the conversion of C2 and factor B to enzymatically active C2a and Bb and thereby prevents the formation of C4b2a and C3bBb, the amplification convertases of the complement cascade. -
Tissue specificity
Expressed on the plasma membranes of all cell types that are in intimate contact with plasma complement proteins. It is also found on the surfaces of epithelial cells lining extracellular compartments, and variants of the molecule are present in body fluids and in extracellular matrix. -
Sequence similarities
Belongs to the receptors of complement activation (RCA) family.
Contains 4 Sushi (CCP/SCR) domains. -
Domain
The first Sushi domain (SCR1) is not necessary for function. SCR2 and SCR4 provide the proper conformation for the active site on SCR3. -
Post-translational
modificationsThe Ser/Thr-rich domain is heavily O-glycosylated. -
Cellular localization
Cell membrane. - Information by UniProt
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Alternative names
- CD 55
- CD55
- CD55 antigen
see all -
Database links
- Entrez Gene: 1604 Human
- Omim: 125240 Human
- SwissProt: P08174 Human
- Unigene: 126517 Human
Images
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SimpleStep ELISA Protocol Diagram
SimpleStep ELISA technology allows the formation of the antibody-antigen complex in one single step, reducing assay time to 90 minutes. Add samples or standards and antibody mix to wells all at once, incubate, wash, and add your final substrate. See protocol for a detailed step-by-step guide.
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Example of human DAF standard curve in Sample Diluent NS.The DAF standard curve was prepared as described in Section 10. Raw data values are shown in the table. Background-subtracted data values (mean +/- SD) are graphed.
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Interpolated concentrations of native DAF in human serum and plasma samples.The concentrations of DAF were measured in duplicates, interpolated from the DAF standard curves and corrected for sample dilution. Undiluted samples are as follows: serum 2.5%, plasma (citrate) 2.5%, plasma (EDTA) 2.5% and plasma (heparin) 2.5%. The interpolated dilution factor corrected values are plotted (mean +/- SD, n=2). The mean DAF concentration was determined to be 58.92 ng/mL in serum, 42.96 ng/mL in plasma (citrate), 68.42 ng/mL in plasma (EDTA), and 50.21 ng/mL in plasma (heparin).
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Interpolated concentrations of native DAF in OVCAR-3 cell culture supernatant samples.The concentrations of DAF were measured in duplicates, interpolated from the DAF standard curves and corrected for sample dilution. Undiluted samples are as follows: OVCAR-3 supernatant 50%. The interpolated dilution factor corrected values are plotted (mean +/- SD, n=2). The mean DAF concentration was determined to be 2261.44 pg/mL in OVCAR-3 supernatant.
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Interpolated concentrations of native DAF in human lung extract based on a 100 µg/mL extract load and human placenta extract based on a 50 µg/mL extract load.The concentrations of DAF were measured in duplicate and interpolated from the DAF standard curve and corrected for sample dilution. The interpolated dilution factor corrected values are plotted (mean +/- SD, n=2). The mean DAF concentration was determined to be 4104.76 pg/mL in lung extract and 2085.73 pg/mL in placenta extract.
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1.25% Serum from ten individual healthy human female donors was measured in duplicate.Interpolated dilution factor corrected values are plotted (mean +/- SD, n=2). The mean DAF concentration was determined to be 48.15 ng/mL with a range of 20.39 – 65.50 ng/mL.
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Sandwich ELISA - Human DAF ELISA Kit (CD55) (ab256405)To learn more about the advantages of recombinant antibodies see here.
