| Field | Specification |
|---|---|
| Target | |
| Alternative names | Negative elongation factor B; NELF-B; Cofactor of BRCA1; NELFB; COBRA1; KIAA1182 |
| UniProt # | |
| Host | |
| Clonality | |
| Isotype | |
| Reactivity | |
| Applications | |
| Immunogen | E. coli-derived human COBRA1 recombinant protein (Position: M1-E252). |
| Molecular weight | |
| Purification | |
| Reconstitution | |
| Cellular localization | |
| Concentration | |
| Form | Lyophilized |
| Storage | |
| Catalog no. (Mfr.) | |
| Main SKU |
Product Overview
This rabbit polyclonal antibody recognizes negative elongation factor B (gene NELFB) in human, mouse and rat samples and is validated for ELISA and Western blot. The predicted molecular weight is 65.7 kDa, and the supplier reports an observed band at about 66 kDa.
NELFB (COBRA1) is a subunit of the NELF complex that holds RNA polymerase II in a paused state near promoters until P-TEFb releases it. NELFB is needed for early embryonic development and helps maintain the undifferentiated state of embryonic stem cells.
| Target | Negative elongation factor B (gene NELFB; UniProt Q8WX92, human) |
|---|---|
| Host / Clonality / Isotype | Rabbit / Polyclonal / Rabbit IgG |
| Reactivity | Human, Mouse, Rat |
| Form | Lyophilized |
| Formulation | Per vial: 4 mg trehalose; 0.9 mg NaCl; 0.2 mg Na2HPO4; 0.05 mg NaN3 |
| Calculated MW | 65.7 kDa |
| Observed MW | 66 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 |
|---|---|
| ELISA | 0.1–0.5 µg/mL |
Samples with a confirmed band (WB): rat kidney tissue, mouse kidney tissue, human MDA-MB-231 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, HRP-conjugated secondary antibody at 1:10000, ECL detection.
Immunogen
Recombinant human COBRA1 fragment (Met1–Glu252), expressed in E. coli.
Reactivity Notes
The supplier lists reactivity with human, mouse and rat. UniProt places negative elongation factor B in the nucleus. Tissue expression noted by UniProt (human): Widely expressed. 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.
