• Product name

    Anti-p21 antibody [HUGO291]
    See all p21 primary antibodies
  • Description

    Rat monoclonal [HUGO291] to p21
  • Host species

  • Specificity

    This antibody is not suitable for use in human.
  • Tested applications

    Suitable for: WB, ELISA, IHC-Pmore details
  • Species reactivity

    Reacts with: Mouse
  • Immunogen

    Immunogen information is not available

  • Positive control

    • Mouse skin papilloma.



Our Abpromise guarantee covers the use of ab107099 in the following tested applications.

The application notes include recommended starting dilutions; optimal dilutions/concentrations should be determined by the end user.

Application Abreviews Notes
WB 1/50. Predicted molecular weight: 18 kDa.
ELISA 1/1000.
IHC-P 1/100.


  • Function

    May be the important intermediate by which p53/TP53 mediates its role as an inhibitor of cellular proliferation in response to DNA damage. Binds to and inhibits cyclin-dependent kinase activity, preventing phosphorylation of critical cyclin-dependent kinase substrates and blocking cell cycle progression. Functions in the nuclear localization and assembly of cyclin D-CDK4 complex and promotes its kinase activity towards RB1. At higher stoichiometric ratios, inhibits the kinase activity of the cyclin D-CDK4 complex.
  • Tissue specificity

    Expressed in all adult human tissues, with 5-fold lower levels observed in the brain.
  • Sequence similarities

    Belongs to the CDI family.
  • Domain

    The PIP-box K+4 motif mediates both the interaction with PCNA and the recuitment of the DCX(DTL) complex: while the PIP-box interacts with PCNA, the presence of the K+4 submotif, recruits the DCX(DTL) complex, leading to its ubiquitination.
    The C-terminal is required for nuclear localization of the cyclin D-CDK4 complex.
  • Post-translational

    Phosphorylation of Thr-145 by Akt or of Ser-146 by PKC impairs binding to PCNA. Phosphorylation at Ser-114 by GSK3-beta enhances ubiquitination by the DCX(DTL) complex.
    Ubiquitinated by MKRN1; leading to polyubiquitination and 26S proteasome-dependent degradation. Ubiquitinated by the DCX(DTL) complex, also named CRL4(CDT2) complex, leading to its degradation during S phase or following UV irradiation. Ubiquitination by the DCX(DTL) complex is essential to control replication licensing and is PCNA-dependent: interacts with PCNA via its PIP-box, while the presence of the containing the 'K+4' motif in the PIP box, recruit the DCX(DTL) complex, leading to its degradation.
  • Cellular localization

    Cytoplasm. Nucleus.
  • Information by UniProt
  • Database links

  • Alternative names

    • CAP20 antibody
    • CDK-interacting protein 1 antibody
    • CDKI antibody
    • CDKN1 antibody
    • Cdkn1a antibody
    • CDN1A_HUMAN antibody
    • CIP1 antibody
    • Cyclin Dependent Kinase Inhibitor 1A antibody
    • Cyclin-dependent kinase inhibitor 1 antibody
    • Cyclin-dependent kinase inhibitor 1A (P21) antibody
    • Cyclin-dependent kinase inhibitor 1A (p21, Cip1) antibody
    • DNA Synthesis Inhibitor antibody
    • MDA-6 antibody
    • MDA6 antibody
    • Melanoma differentiation-associated protein 6 antibody
    • Melanoma differentiation-associated protein antibody
    • p21 antibody
    • P21 protein antibody
    • p21CIP1 antibody
    • p21Cip1/Waf1 antibody
    • p21WAF antibody
    • PIC1 antibody
    • SDI1 antibody
    • SLC12A9 antibody
    • WAF1 antibody
    • Wild type p53 activated fragment 1 (WAF1) antibody
    • Wild type p53 activated fragment 1 antibody
    • Wildtype p53-activated fragment 1 antibody
    see all


  • All lanes : Anti-p21 antibody [HUGO291] (ab107099) at 1/50 dilution

    Lane 1 : TT243 MEFs (non-irradiated) at 18.83 µg
    Lane 2 : TT243 MEFs (irradiated with 10 Gy) at 20.8 µg
    Lane 3 : p21-/- KO MEFs at 60 µg
    Lane 4 : P21 WT MEFs at 75 µg
    Lane 5 : HEK-V5-mp21 transfected cells at 20 µg
    Lane 6 : HEK-V5-mp15 transfected cells at 20 µg

    Predicted band size: 18 kDa

  • Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) analysis of mouse p21WT fibrosarcoma and mouse p21KO fibrosarcoma tissue sections labeling p21 with ab107099.

  • Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) analysis of Hek-V5-mp21 transfected cells labelling p21 with ab107099. Nuclear staining was observed in Hek-V5-mp21 cytospins. Labeling with the anti-V5 mAb confirmed the efficiency of transfection. Cytospin preparation of human CD8 was used as a negative control.

  • ab107099 at 1/100 staining p21 in conditional TRF1 knock out Mouse skin tissue by Immunohistochemistry.

  • ab107099 at 1/100 staining p21 in Mouse skin papilloma tissue by Immunohistochemistry.


This product has been referenced in:

  • Tominaga T  et al. Senescence-associated-ß-galactosidase staining following traumatic brain injury in the mouse cerebrum. PLoS One 14:e0213673 (2019). Read more (PubMed: 30856215) »
  • Li M  et al. APE1 deficiency promotes cellular senescence and premature aging features. Nucleic Acids Res 46:5664-5677 (2018). Read more (PubMed: 29750271) »
See all 5 Publications for this product

Customer reviews and Q&As


Yesterday we spoke of the recommended WB dilution for ab107099 listed as 1/2 on the datasheet. I spoke with the lab, and they responded that with the purified form of the antibody the recommended WB dilution is 1/50. The dilutions used in the images on the datsheet were for the unpurified hybridoma supernatant, which is why they are listed as 1/2 for WB and "neat" for IHC.

I apologize for the confusion and lack of detail on the datasheet, we will correct the datasheet error shortly.

Read More

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