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Phospho-Stat3 (Tyr705) (D3A7) XP® Rabbit mAb (Alexa Fluor® 488 Conjugate) #4323
Gallery: Phospho-Stat3 (Tyr705) (D3A7) XP® Rabbit mAb (Alexa Fluor® 488 Conjugate) #4323
Flow Cytometry, Methanol Permeabilization Protocol for Direct Conjugates
A. Solutions and Reagents
NOTE: Prepare solutions with reverse osmosis deionized (RODI) or equivalent grade water.
- 20X Phosphate Buffered Saline (PBS): (#9808) To prepare 1 L 1X PBS: add 50 ml 20X PBS to 950 ml dH2O, mix.
- 16% Formaldehyde (methanol free).
- 100% methanol.
- Incubation Buffer: Dissolve 0.5 g Bovine Serum Albumin (BSA) (#9998) in 100 ml 1X PBS. Store at 4°C.
NOTE: If using whole blood, lyse red blood cells and wash by centrifugation prior to fixation.
- Collect cells by centrifugation and aspirate supernatant.
- Resuspend cells in 0.5-1 ml 1X PBS. Add formaldehyde to obtain a final concentration of 4%.
- Fix for 15 min at room temperature.
- Wash by centrifugation with excess 1X PBS. Discard supernatant in appropriate waste container. Resuspend cells in 0.5-1 ml 1X PBS.
- Permeabilize cells by adding ice-cold 100% methanol slowly to pre-chilled cells, while gently vortexing, to a final concentration of 90% methanol.
- Incubate 30 min on ice.
- Proceed with immunostaining (Section D) or store cells at -20°C in 90% methanol.
- Aliquot desired number of cells into tubes or wells.
- Wash cells by centrifugation in excess 1X PBS to remove methanol. Discard supernatant in appropriate waste container. Repeat if necessary.
- Resuspend cells in 100 µl of diluted antibody conjugate (prepared in incubation buffer at the recommended dilution).
- Incubate for 1 hr at room temperature. Protect from light.
- Wash by centrifugation in incubation buffer. Discard supernatant. Repeat.
- Resuspend cells in 1X PBS and analyze on flow cytometer; alternatively, for DNA staining, proceed to optional DNA stain (Section E).
E. Optional DNA Dye
- Resuspend cells in 0.5 ml of DNA dye (e.g. Propidium Iodide (PI)/RNase Staining Solution #4087).
- Incubate for at least 5 min at room temperature.
- Analyze cells in DNA staining solution on flow cytometer.
posted July 2009
revised June 2017
Phospho-Stat3 (Tyr705) (D3A7) XP® Rabbit mAb (Alexa Fluor® 488 Conjugate) detects endogenous levels of Stat3 only when phosphorylated at Tyr705. This antibody does not cross-react with phospho-EGFR or the corresponding phospho-tyrosines of other Stat proteins.Species Reactivity: Human, Mouse, Rat, Monkey Species predicted to react based on 100% sequence homology: Hamster, Bovine, Pig, Horse
Monoclonal antibody is produced by immunizing animals with a synthetic phosphopeptide corresponding to residues surrounding Tyr705 of mouse Stat3. The antibody was conjugated to Alexa Fluor® 488 under optimal conditions with an F/P ratio of 2-6.
This Cell Signaling Technology antibody conjugated to Alexa Fluor® 488 fluorescent dye and tested in-house for direct flow cytometric analysis of human cells. The unconjugated antibody #9145 reacts with Phospho- Stat3 (Tyr705) from human, mouse and rat. CST expects that Phospho-Stat3 (Tyr705) (D3A7) XP® Rabbit mAb (Alexa Fluor® 488 Conjugate) will also recognize Phospho-Stat3 in these species.
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).
For Research Use Only. Not For Use In Diagnostic Procedures. Cell Signaling Technology is a trademark of Cell Signaling Technology, Inc. XP is a registered trademark of Cell Signaling Technology, Inc. The Alexa Fluor dye antibody conjugates in this product are sold under license from Life Technologies Corporation for research use only, except for use in combination with DNA microarrays. The Alexa Fluor® dyes (except for Alexa Fluor® 430 dye) are covered by pending and issued patents. Alexa Fluor® is a registered trademark of Molecular Probes, Inc.