| Field | Specification |
|---|---|
| Target | |
| Alternative names | Complement factor I;3.4.21.45;C3B/C4B inactivator;Complement factor I heavy chain;Complement factor I light chain;CFI;IF; |
| UniProt # | |
| Host | |
| Clonality | |
| Isotype | |
| Reactivity | |
| Applications | |
| Immunogen | E. coli-derived human Factor I recombinant protein (Position: K19-D220). Human Factor I shares 70.7% and 71.2% amino acid (aa) sequence identity with mouse and rat Factor I, respectively. |
| Molecular weight | |
| Purification | |
| Reconstitution | |
| Cellular localization | |
| Concentration | |
| Form | Lyophilized |
| Storage | |
| Catalog no. (Mfr.) | |
| Main SKU |
Product Overview
This rabbit polyclonal antibody recognizes complement factor I (gene CFI) in human and rat samples and is validated for flow cytometry, IHC, ICC/IF and Western blot. The predicted molecular weight is 65.8 kDa; the supplier reports observed bands at 75 kDa, 45 kDa.
Complement factor I (CFI) is a plasma serine protease that inactivates C3b and C4b by cleaving them, with the help of cofactors such as factor H and CD46. It thereby limits all complement pathways and protects host tissues, and its deficiency or variants are studied in infection susceptibility and complement-mediated kidney and eye disease.
| Target | Complement factor I (gene CFI; UniProt P05156, human) |
|---|---|
| Host / Clonality / Isotype | Rabbit / Polyclonal / Rabbit IgG |
| Reactivity | Human, Rat |
| Form | Lyophilized |
| Formulation | Per vial: 0.9 mg NaCl; 0.2 mg Na2HPO4; 0.05 mg NaN3; plus stabilizers |
| Calculated MW | 65.8 kDa |
| Observed MW | 75 kDa, 45 kDa |
| Storage | As supplied: −20 °C for up to 12 months from receipt. After reconstitution: 4 °C for up to 1 month, or aliquot and keep at −20 °C for up to 6 months. Avoid repeated freeze–thaw cycles. |
Validated Applications
| Western blot | 0.1–0.5 µg/mL (Human, Rat) |
|---|---|
| IHC (frozen sections) | 0.5–1 µg/mL (Human) |
| Immunocytochemistry / Immunofluorescence | 0.5–1 µg/mL (Human) |
| Flow cytometry (fixed cells) | 1–3 µg/1×106 cells (Human) |
Samples with a confirmed band (WB): rat liver tissue, HeLa cells.
Recommended loading (WB): 20–40 µg of total protein per lane.
Conditions in the example images (WB): 5–20% gradient SDS-PAGE under reducing conditions, 50 µg lysate per lane, transfer to nitrocellulose membrane, blocking in 5% non-fat milk, primary antibody at 0.5 µg/mL overnight at 4 °C, HRP-conjugated secondary antibody at 1:10000, ECL detection.
Samples with a confirmed signal (flow cytometry): U-87 cells, HepG2 cells.
Immunogen
Recombinant human Factor I fragment (Lys19–Asp220), expressed in E. coli. Sequence identity with the mouse and rat orthologs: 70.7% and 71.2%, respectively.
Reactivity Notes
The supplier lists reactivity with human and rat. UniProt describes complement factor I as a secreted protein. Tissue expression noted by UniProt (human): Expressed in the liver by hepatocytes. The samples tested by the supplier (listed above) are a practical starting point for positive controls.
Safety
Customization & Add-ons: Can’t find the antibody you need—or require a custom format for your assay? We can help you source the best match or support custom antibody solutions for diverse research needs, including species and isotype selection, conjugations and labeling (e.g., HRP/AP, biotin, fluorophores), purification grade options (Protein A/G, affinity purified), formulation preferences (buffer selection, carrier-free, glycerol-free), custom concentrations and aliquoting, low-endotoxin options for cell-based work, and application-focused QC/validation support (project dependent). Click Talk to a Scientist to submit a request, email us at support@biohippo.com, or explore our Research Services for additional support—our team will follow up with feasibility details and next steps.
