Cell Signaling Technology

Product Pathways - PathScan ELISA

PathScan® Total p21 Waf1/Cip1 Sandwich ELISA Antibody Pair #7856

Kit Includes Volume Cap Color
p21 Waf1/Cip1 CaptureAb (100X) 0.4 ml Pink
p21 Waf1/Cip1 Detection Ab (100X) 0.4 ml Blue
Anti-rabbit IgG, HRP-linked Antibody (1000X) 0.04 ml Red

Capture and detection antibodies are stored at 4°C. HRP-linked secondary reagent is stored at -20°C.

Species Cross-Reactivity

H

Reactivity Key:  H=Human
Species enclosed in parentheses are predicted to react based on 100% sequence homology.

Important Ordering Details

Product is assembled upon order to ensure maximum activity. Domestic: Please allow up to two weeks for your order to be processed and shipped. International: Please allow up to three weeks, depending on the country, for your order to be processed and shipped.

Protocols

Description

CST's PathScan® Total p21 Waf1/Cip1 Sandwich ELISA Antibody Pair is being offered as an economical alternative to our PathScan®Total p21 Waf1/Cip1 Sandwich ELISA Kit #7167. Capture and detection antibodies (100X stocks) and HRP-conjugated secondary antibody (1000X stock) are supplied. Sufficient reagents are supplied for 4 x 96 well ELISAs. The p21 Waf1/Cip1 mouse capture antibody is coated on a 96 well microplate in PBS overnight. After blocking, cell lysates are added followed by a p21 Waf1/Cip1 rabbit detection antibody and anti-rabbit IgG, HRP conjugated antibody. HRP substrate (TMB) is added for color development. The magnitude of the absorbance for this developed color is proportional to the quantity of total p21 Waf1/Cip1 protein.

Specificity / Sensitivity

For Antibody Pair specificity and sensitivity, please refer to the corresponding PathScan® Sandwich ELISA Kit. Note: This antibody pair detects proteins from the indicated species, as determined through in-house testing, but may also detect homologous proteins from other species.

The relationship between lysate protein concentration from 293 cells and the absorbance at 450 nm using PathScan® Total p21 Waf1/Cip1 Sandwich ELISA Antibody Pair is shown.

Background

The tumor suppressor protein p21 Waf1/Cip1 acts as an inhibitor of cell cycle progression. It functions in stoichiometric relationships forming heterotrimeric complexes with cyclins and cyclin-dependent kinases. In association with CDK2 complexes, it serves to inhibit kinase activity and block progression through G1/S (1). However, p21 may also enhance assembly and activity in complexes of CDK4 or CDK6 and cyclin D (2). The carboxy-terminal region of p21 is sufficient to bind and inhibit PCNA, a subunit of DNA polymerase, and may coordinate DNA replication with cell cycle progression (3). Upon UV damage or during cell cycle stages when cdc2/cyclin B or CDK2/cyclin A are active, p53 is phosphorylated and upregulates p21 transcription via a p53-responsive element (4). Protein levels of p21 are downregulated through ubiquitination and proteasomal degradation (5).

  1. Pestell, R.G. et al. (1999) Endocrine Rev. 20, 501-534.
  2. Cheng, J. et al. (1999) EMBO J. 18, 1571-1583.
  3. Flores-Rozas, H. et al. (1994) Proc. Natl. Acad. Sci. USA 91, 8655-8659.
  4. Wang, Y. and Prives, C. (1995) Nature 376, 88-91.
  5. Sheaff, R.J. et al. (2000) Cell 5, 403-410.

Application References

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Companion Products

For Research Use Only. Not For Use In Diagnostic Procedures.

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