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H M Mk
Product Includes Volume Solution Color
p53 Mouse mAb coated microwells 96 tests
Acetylated-Lysine Rabbit Detection Antibody 11 ml Green
Anti-rabbit IgG, HRP-linked Antibody 11 ml Red
TMB Substrate 7004 11 ml Colorless
STOP Solution 7002 11 ml Colorless
Sealing Tape 2 sheets
ELISA Wash Buffer (20X) 25 ml Colorless
ELISA Sample Diluent 25 ml Blue
Cell Lysis Buffer (10X) 9803 15 ml Yellowish

ELISA Colorimetric

NOTE: Refer to product-specific datasheets or product webpage for assay incubation temperature.

A. Solutions and Reagents

NOTE: Prepare solutions with reverse osmosis deionized (RODI) or equivalent grade water.

  1. 20X Phosphate Buffered Saline (PBS): (#9808) To prepare 1 L PBS: add 50 ml 10X PBS to 950 ml dH2O, mix.
  2. Bring all microwell strips to room temperature before use.
  3. Prepare 1X Wash Buffer by diluting 20X Wash Buffer (included in each PathScan® Sandwich ELISA Kit) in dH2O.
  4. 1X Cell Lysis Buffer: 10X Cell Lysis Buffer (#9803): To prepare 10 ml of 1X Cell Lysis Buffer, add 1 ml of 10X Cell Lysis Buffer to 9 ml of dH2O, mix. Buffer can be stored at 4°C for short-term use (1–2 weeks).

    Recommended: Add 1 mM phenylmethylsulfonyl fluoride (PMSF) (#8553) immediately before use.

    NOTE: Refer to product-specific datasheet or webpage for lysis buffer recommendation.

  5. TMB Substrate: (#7004).
  6. STOP Solution: (#7002).

B. Preparing Cell Lysates

For adherent cells

  1. Aspirate media when the culture reaches 80–90% confluence. Treat cells by adding fresh media containing regulator for desired time.
  2. Remove media and rinse cells once with ice-cold 1X PBS.
  3. Remove PBS and add 0.5 ml ice-cold 1X cell lysis buffer plus 1 mM PMSF to each plate (10 cm diameter) and incubate the plate on ice for 5 min.
  4. Scrape cells off the plate and transfer to an appropriate tube. Keep on ice.
  5. Sonicate lysates on ice.
  6. Microcentrifuge for 10 min (x14,000 rpm) at 4°C and transfer the supernatant to a new tube. The supernatant is the cell lysate. Store at -80°C in single-use aliquots.

For suspension cells

  1. Remove media by low speed centrifugation (~1,200 rpm) when the culture reaches 0.5–1.0 x 106 viable cells/ml. Treat cells by adding fresh media containing regulator for desired time.
  2. Collect cells by low speed centrifugation (~1,200 rpm) and wash once with 5–10 ml ice-cold 1X PBS.
  3. Cells harvested from 50 ml of growth media can be lysed in 2.0 ml of 1X cell lysis buffer plus 1 mM PMSF.
  4. Sonicate lysates on ice.
  5. Microcentrifuge for 10 min (x14,000 rpm) at 4°C and transfer the supernatant to a new tube. The supernatant is the cell lysate. Store at -80°C in single-use aliquots.

C. Test Procedure

  1. After the microwell strips have reached room temperature, break off the required number of microwells. Place the microwells in the strip holder. Unused microwells must be resealed in the storage bag and stored at 4°C immediately.
  2. Cell lysates can be undiluted or diluted with sample diluent (supplied in each PathScan® Sandwich ELISA Kit, blue color). Individual datasheets or product webpage for each kit provide information regarding an appropriate dilution factor for lysates and kit assay results.
  3. Add 100 µl of each undiluted or diluted cell lysate to the appropriate well. Seal with tape and press firmly onto top of microwells. Incubate the plate for 2 hr at 37°C. Alternatively, the plate can be incubated overnight at 4°C.
  4. Gently remove the tape and wash wells:
    1. Discard plate contents into a receptacle.
    2. Wash 4 times with 1X wash buffer, 200 µl each time per well.
    3. For each wash, strike plates on fresh paper towels hard enough to remove the residual solution in each well, but do not allow wells to completely dry at any time.
    4. Clean the underside of all wells with a lint-free tissue.
  5. Add 100 µl of detection antibody (green color) to each well. Seal with tape and incubate the plate at 37°C for 1 hr.
  6. Repeat wash procedure (Section C, Step 4).
  7. Add 100 µl of HRP-linked secondary antibody (red color) to each well. Seal with tape and incubate the plate for 30 min at 37°C.
  8. Repeat wash procedure (Section C, Step 4).
  9. Add 100 µl of TMB substrate to each well. Seal with tape and incubate the plate for 10 min at 37°C or 30 min at 25°C.
  10. Add 100 µl of STOP solution to each well. Shake gently for a few seconds.

    NOTE: Initial color of positive reaction is blue, which changes to yellow upon addition of STOP solution.

  11. Read results
    1. Visual Determination: Read within 30 min after adding STOP solution.
    2. Spectrophotometric Determination: Wipe underside of wells with a lint-free tissue. Read absorbance at 450 nm within 30 min after adding STOP solution.

posted June 2005

revised November 2013

protocol id: 21

Product Description

The PathScan® Acetylated p53 Sandwich ELISA Kit is a solid phase sandwich enzyme-linked immunosorbent assay (ELISA) that detects endogenous levels of acetylated lysines on p53. A p53 Mouse monoclonal Antibody has been coated onto the microwells. After incubation with cell lysates, the p53 is captured by the coated antibody. Following extensive washing, Acetylated-Lysine Rabbit monoclonal Antibody is added to detect the acetylated lysines on the p53 protein. Anti-rabbit IgG, HRP linked Antibody is then used to recognize the bound detection antibody. HRP substrate, TMB is added to develop color. The magnitude of the absorbance for this developed color is proportional to the quantity of acetylated p53.

Antibodies in kit are custom formulations specific to kit.

Specificity / Sensitivity

CST's PathScan® Acetylated p53 Sandwich ELISA Kit detects endogenous levels of Acetylated p53. Using this Sandwich ELISA Kit #7236, acetylated lysines on p53 are detected when treated with TSA in COS cells. However, the levels of p53 remain unchanged, as shown by Western analysis (Figure 1). NIH/3T3 and 293 cells treated with TSA show similar results (data not shown). This kit detects proteins from the indicated species, as determined through in-house testing, but may also detect homologous proteins from other species.

Species Reactivity: Human, Mouse, Monkey

The p53 tumor suppressor protein plays a major role in cellular response to DNA damage and other genomic aberrations. Activation of p53 can lead to either cell cycle arrest and DNA repair or apoptosis (1). p53 is phosphorylated at multiple sites in vivo and by several different protein kinases in vitro (2,3). DNA damage induces phosphorylation of p53 at Ser15 and Ser20 and leads to a reduced interaction between p53 and its negative regulator, the oncoprotein MDM2 (4). MDM2 inhibits p53 accumulation by targeting it for ubiquitination and proteasomal degradation (5,6). p53 can be phosphorylated by ATM, ATR, and DNA-PK at Ser15 and Ser37. Phosphorylation impairs the ability of MDM2 to bind p53, promoting both the accumulation and activation of p53 in response to DNA damage (4,7). Chk2 and Chk1 can phosphorylate p53 at Ser20, enhancing its tetramerization, stability, and activity (8,9). p53 is phosphorylated at Ser392 in vivo (10,11) and by CAK in vitro (11). Phosphorylation of p53 at Ser392 is increased in human tumors (12) and has been reported to influence the growth suppressor function, DNA binding, and transcriptional activation of p53 (10,13,14). p53 is phosphorylated at Ser6 and Ser9 by CK1δ and CK1ε both in vitro and in vivo (13,15). Phosphorylation of p53 at Ser46 regulates the ability of p53 to induce apoptosis (16). Acetylation of p53 is mediated by p300 and CBP acetyltransferases. Inhibition of deacetylation suppressing MDM2 from recruiting HDAC1 complex by p19 (ARF) stabilizes p53. Acetylation appears to play a positive role in the accumulation of p53 protein in stress response (17). Following DNA damage, human p53 becomes acetylated at Lys382 (Lys379 in mouse) in vivo to enhance p53-DNA binding (18). Deacetylation of p53 occurs through interaction with the SIRT1 protein, a deacetylase that may be involved in cellular aging and the DNA damage response (19).

1.  Chehab NH et al. (1999) Proc Natl Acad Sci U S A 96, 13777–82

2.  Levine, A.J. (1997) Cell 88, 323-31.

3.  Meek, D.W. (1994) Semin. Cancer Biol. 5, 203-210.

4.  Milczarek, G.J. et al. (1997) Life Sci. 60, 1-11.

5.  Shieh, S.Y. et al. (1997) Cell 91, 325-334.

6.  Honda, R. et al. (1997) FEBS Lett. 420, 25-27.

7.  Tibbetts, R.S. et al. (1999) Genes Dev. 13, 152-157.

8.  Shieh, S.Y. et al. (1999) EMBO J. 18, 1815-1823.

9.  Hirao, A. et al. (2000) Science 287, 1824-1827.

10.  Hao, M. et al. (1996) J. Biol. Chem. 271, 29380-29385.

11.  Lu, H. et al. (1997) Mol. Cell. Biol. 17, 5923-5934.

12.  Ullrich, S.J. et al. (1993) Proc. Natl. Acad. Sci. USA 90, 5954-5958.

13.  Kohn, K.W. (1999) Mol. Biol. Cell 10, 2703-2734.

14.  Lohrum, M. and Scheidtmann, K.H. (1996) Oncogene 13, 2527-2539.

15.  Sakaguchi, K. et al. (1998) Genes Dev 12, 2831-41.

16.  Knippschild, U. et al. (1997) Oncogene 15, 1727-1736.

17.  Oda, K. et al. (2000) Cell 102, 849-862.

18.  Ito, A. et al. (2001) EMBO J. 20, 1331-1340.

19.  Solomon, J.M. et al. (2006) Mol. Cell. Biol. 26, 28-38.

Entrez-Gene Id 7157
Swiss-Prot Acc. P04637

For Research Use Only. Not For Use In Diagnostic Procedures.
Cell Signaling Technology® is a trademark of Cell Signaling Technology, Inc.
PathScan® is a trademark of Cell Signaling Technology, Inc.