Description
Key facts
Detection method:Colorimetric,
Sample types:Saliva, Plasma, Milk, Serum,
Reacts with:Human,
Assay type:Competitive,
Sensitivity:= 0.28 µg/mL,
Range:0.375 - 24 µg/mL,
Assay time:3h,
Assay Platform:Microplate
Product details:
Abcam's Complement Factor I Human
in vitro
competitive ELISA (Enzyme-Linked Immunosorbent Assay) kit is designed for the quantitative measurement of Complement Factor I levels in plasma, serum, milk and saliva samples.
A Complement Factor I specific antibody has been precoated onto 96-well plates and blocked. Standards or test samples are added to the wells and subsequently biotinylated Complement Factor I is added and then followed by washing with wash buffer. Streptavidin-Peroxidase Conjugate 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 Factor I captured in plate.
The entire kit may be stored at -20°C for long term storage before reconstitution - Avoid repeated freeze-thaw cycles.
Properties and Storage Information:
Shipped at conditions-Blue Ice, Appropriate short-term storage conditions--20°C, Appropriate long-term storage conditions-Multi, Storage information-Please refer to protocols
Supplementary Information:
This supplementary information is collated from multiple sources and compiled automatically.
Factor I also known as Complement Factor I (CFI) is a serine protease involved in the complement system. Its molecular mass is approximately 88 kDa consisting of a heavy and a light chain linked by a disulfide bond. This protein is mainly expressed in the liver and circulates in the plasma. Factor I inhibits the complement pathways by cleaving complement components C3b and C4b preventing the formation of C3 and C5 convertases.
Biological function summary
Factor I plays a role in maintaining immune homeostasis by preventing excessive complement activation. It acts within a complex that includes cofactors such as Factor H Complement Factor 4 binding protein (C4BP) and Membrane Cofactor Protein (MCP). These interactions allow Factor I to selectively degrade activated complement components ensuring that complement activity is kept in check to avoid host cell damage.
Pathways
Factor I operates in both the classical and alternative complement pathways. In the classical pathway it regulates C3b and C4b breakdown to control the formation of the C3 convertase. In the alternative pathway Factor I works in conjunction with Factor H to degrade C3b. This regulation is important to prevent runaway activation protecting healthy tissue from complement-mediated damage.
Factor I deficiencies can lead to conditions like atypical hemolytic uremic syndrome (aHUS) and age-related macular degeneration (AMD). In aHUS insufficient Factor I activity permits unregulated complement activation leading to thrombotic microangiopathy. In AMD aberrant complement activation contributes to retinal damage and degeneration. These conditions illustrate the need for balanced Factor I activity to prevent disease.
