| Field | Specification |
|---|---|
| Mfr No | |
| Clonality | |
| Concentration | |
| Conjugate | |
| Host | |
| Immunogen | Recombinant fusion protein of human p21 (NP_000380.1). |
| Isotype | |
| Product Type | |
| Shipping | |
| Storage | |
| UniProt # |
Product Overview
This gene encodes a potent cyclin-dependent kinase inhibitor. The encoded protein binds to and inhibits the activity of cyclin-cyclin-dependent kinase2 or -cyclin-dependent kinase4 complexes, and thus functions as a regulator of cell cycle progression at G1. The expression of this gene is tightly controlled by the tumor suppressor protein p53, through which this protein mediates the p53-dependent cell cycle G1 phase arrest in response to a variety of stress stimuli. This protein can interact with proliferating cell nuclear antigen, a DNA polymerase accessory factor, and plays a regulatory role in S phase DNA replication and DNA damage repair. This protein was reported to be specifically cleaved by CASP3-like caspases, which thus leads to a dramatic activation of cyclin-dependent kinase2, and may be instrumental in the execution of apoptosis following caspase activation. Mice that lack this gene have the ability to regenerate damaged or missing tissue. Multiple alternatively spliced variants have been found for this gene.
Validated Applications & Recommended Dilutions
| Application | Recommended Dilution |
|---|---|
| WB | 1:500-1:2000 |
| IF | 1:50-1:200 |
Antibody Specifications
| Target | p21 |
|---|---|
| Host Species | Rabbit |
| Clonality | Polyclonal |
| Isotype | IgG |
| Conjugate | Unconjugated |
| Purification | Affinity Purification |
| Concentration | 1mg/mL |
| Molecular Weight | Calculated 21kDa; Observed 21kDa |
Immunogen
Recombinant fusion protein of human p21 (NP_000380.1). UniProt: P38936.
Species Reactivity & Cross-Reactivity
Validated for: Human, Mouse, Rat. Verify suitability in your sample type prior to use. For species or applications not listed in the datasheet, consult our technical team before purchase.
Storage & Handling
Store at -20℃ Valid for 12 months. Avoid freeze / thaw cycles.
Storage Buffer: PBS with 0.02% sodium azide, 50% glycerol, pH7.3.
Related Products
Browse additional antibodies targeting p21 and complementary reagents — including secondary antibodies, blocking buffers, and detection kits — available through BioHippo.
The recommended starting dilution for Western Blot is WB 1:500-1:2000;IF 1:50-1:200. Optimal dilution should be determined empirically for each laboratory setup, sample type, and detection system. Use freshly prepared lysates with protease inhibitors; add phosphatase inhibitors if studying phosphorylation-dependent forms of p21. Expected band size: Calculated 21kDa, Observed 21kDa. If background is high, increase blocking (5% non-fat milk or BSA in TBST) and/or increase wash stringency.
For intracellular targets including most nuclear and cytoplasmic proteins, fix cells with 4% paraformaldehyde (15 min, room temperature) followed by permeabilization with 0.1–0.2% Triton X-100 or saponin (5–10 min). For surface membrane targets, fixation without permeabilization may be sufficient. Block with 5–10% normal serum (matching the secondary antibody host species) for 30–60 min. Incubate primary antibody at the recommended dilution (WB 1:500-1:2000;IF 1:50-1:200) at 4°C overnight or 1–2 h at room temperature. Confirm nuclear/cytoplasmic localization of p21 against published protein databases before designing your protocol.
This antibody has been experimentally validated in: Human, Mouse, Rat. Cross-reactivity with other species has not been systematically evaluated. If your sample species is not listed, assess immunogen sequence homology to your target species ortholog. The immunogen used is: "Recombinant fusion protein of human p21 (NP_000380.1)." — higher sequence identity between species increases the probability of cross-reactivity, but experimental validation with appropriate controls is necessary before drawing scientific conclusions.
Store at -20℃ Valid for 12 months. Avoid freeze / thaw cycles. Storage Buffer: PBS with 0.02% sodium azide, 50% glycerol, pH7.3.. To maintain antibody activity, avoid repeated freeze-thaw cycles. Aliquot into single-use volumes before first freeze. If working with the antibody frequently, keep a working stock at 4°C for up to 4 weeks — add 0.02% sodium azide to the working stock as a bacteriostatic agent if azide is not already present in the buffer. Monitor performance against a validated positive control when transitioning between storage aliquots or lots.
Polyclonal antibodies are produced from immunized animals and may exhibit some degree of lot-to-lot variation in titer, background, and sensitivity. Each production lot is tested for performance against established acceptance criteria. When transitioning to a new lot, run a side-by-side pilot comparison against your previous lot using a validated positive control sample before updating your standard protocol. If significant performance differences are observed, contact our technical support team — titer adjustments may resolve the issue in most cases.
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.
