Cell Signaling Technology

Product Pathways - PathScan ELISA

PathScan® Total Stat3 Sandwich ELISA Kit #7305

When ordering five or more kits, please contact us for processing time and pricing at sales@cellsignal.com.

Kit Includes Volume Solution Color
Stat3 Rabbit mAb Coated Microwells 96 tests
Stat3 Mouse Detection mAb 11 ml Green
Anti-mouse 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
Cell Lysis Buffer (10X) #9803 15 ml Yellowish

Note: 12 8-well modules –Each module is designed to break apart for 8 tests.
Note: Kit should be stored at 4°C with the exception of Cell Lysis Buffer, which is stored at –20°C (packaged separately).

Species Cross-Reactivity

H M R Mk

Reactivity Key:  H=Human  M=Mouse  R=Rat  Mk=Monkey
Species enclosed in parentheses are predicted to react based on 100% sequence homology.

Description

The PathScan® Total Stat3 Sandwich ELISA Kit is a solid phase sandwich enzyme-linked immunosorbent assay (ELISA) that detects endogenous levels of Stat3 protein. A Stat3 rabbit mAb has been coated onto the microwells. After incubation with cell lysates, Stat3 protein is captured by the coated antibody. Following extensive washing, a Stat3 mouse mAb is added to detect captured Stat3 protein. Anti-mouse 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 Stat3 protein.Antibodies in kit are custom formulations specific to kit.

Specificity / Sensitivity

PathScan® Total Stat3 Sandwich ELISA Kit detects endogenous levels of Stat3 protein in human cells, as shown in Figure 1. The kit sensitivity is shown in Figure 2. This kit detects proteins from the indicated species, as determined through in-house testing, but may also detect homologous proteins from other species.

ELISA - Western correlation

ELISA - Western correlation

Figure 1: Treatment of A-431 cells with EGF stimulates phosphorylation of Stat3 at Ser727, as detected by PathScan® Phospho-Stat3 (Ser727) Sandwich ELISA Kit #7995, but does not affect levels of total Stat3 protein detected by PathScan® Total Stat3 Sandwich ELISA Kit #7305. The absorbance readings at 450 nm are shown in the top figure, while the corresponding western blots using Stat3 Antibody #9132 (left panel) or Phospho-Stat3 (Ser727) #9134 (right panel) is shown in the bottom figure.

Sensitivity

Sensitivity

Figure 2: The relationship between protein concentration of lysates from untreated and EGF-treated A-431 cells and the absorbance at 450 nm is shown. After starvation, A-431 cells (85% confluence) were treated with EGF (100 ng/ml) for 5 min at 37ºC and then lysed.

Background

The Stat3 transcription factor is an important signaling molecule for many cytokines and growth factor receptors (1) and is required for murine fetal development (2). Research studies have shown that Stat3 is constitutively activated in a number of human tumors (3,4) and possesses oncogenic potential (5) and anti-apoptotic activities (3). Stat3 is activated by phosphorylation at Tyr705, which induces dimerization, nuclear translocation, and DNA binding (6,7). Transcriptional activation seems to be regulated by phosphorylation at Ser727 through the MAPK or mTOR pathways (8,9). Stat3 isoform expression appears to reflect biological function as the relative expression levels of Stat3α (86 kDa) and Stat3β (79 kDa) depend on cell type, ligand exposure, or cell maturation stage (10). It is notable that Stat3β lacks the serine phosphorylation site within the carboxy-terminal transcriptional activation domain (8).

  1. Heim, M.H. (2001) J Recept Signal Transduct Res 19, 75-120.
  2. Takeda, K. et al. (1997) Proc Natl Acad Sci U S A 94, 3801-4.
  3. Catlett-Falcone, R. et al. (1999) Immunity 10, 105-15.
  4. Garcia, R. and Jove, R. (1998) J Biomed Sci 5, 79-85.
  5. Bromberg, J.F. et al. (1999) Cell 98, 295-303.
  6. Darnell, J.E. et al. (1994) Science 264, 1415-21.
  7. Ihle, J.N. (1995) Nature 377, 591-4.
  8. Wen, Z. et al. (1995) Cell 82, 241-50.
  9. Yokogami, K. et al. (2000) Curr Biol 10, 47-50.
  10. Biethahn, S. et al. (1999) Exp Hematol 27, 885-94.

Application References

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Protocols

Companion Products

Rabbit monoclonal antibody is produced under license (granting certain rights including those under U. S. Patents No. 5,675,063 and 7,429,487) from Epitomics, Inc.

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

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