STAT3 (Phospho-Ser727) Fluorometric Cell-Based ELISA Kit

Description

Description

STAT3 (Phospho-Ser727) Cell-Based ELISA Kit

The STAT3 (Phospho-Ser727) Cell-Based ELISA Kit is a convenient, lysate- free, high throughput and sensitive assay kit that can monitor STAT3 phosphorylation and expression profile in cells. The kit can be used for measuring the relative amounts of phosphorylated STAT3 in cultured cells as well as screening for the effects that various treatments, inhibitors (ie. siRNA or chemicals), or activators have on STAT3 phosphorylation.

How does our STAT3 (Phospho-Ser727) Fluorometric Cell-Based ELISA Kit work?

Qualitative determination of STAT3 (Phospho-Ser727) concentration is achieved by an indirect ELISA format. In essence, STAT3 (Phospho-Ser727) is captured by STAT3 (Phospho-Ser727)-specific primary (1°) antibodies while Dye 1-conjugated and Dye 2-conjugated secondary (2°) antibodies bind the Fc region of the 1° antibody. Through this binding, the dye conjugated to the 2° antibody can emit light at a certain wavelength given proper excitation, hence allowing for a fluorometric detection method. Due to the qualitative nature of the Cell-Based ELISA, multiple normalization methods are needed:

1.	A monoclonal antibody specific for human GAPDH is included to serve as an internal positive control in normalizing the target RFU values.
2.	An antibody against the nonphosphorylated counterpart of STAT3 (Phospho-Ser727) is also provided for normalization purposes. The RFU values obtained for non-phosphorylated STAT3 can be used to normalize the RFU value for phosphorylated STAT3.

STAT3 (Phospho-Ser727) Fluorometric Cell-Based ELISA Kit -Information

Product Name:	STAT3 (Phospho-Ser727) Fluorometric Cell-Based ELISA Kit
Product Code/SKU:	FBCAB00080
Description:	The STAT3 (Phospho-Ser727) Fluorometric Cell-Based Phospho ELISA Kit is a convenient, lysate-free, high throughput and sensitive assay kit that can monitor STAT3 (Phospho-Ser727) protein phosphorylation and expression profile in cells. The kit can be used for measuring the relative amounts of phosphorylated STAT3 (Phospho-Ser727) in cultured cells as well as screening for the effects that various treatments, inhibitors (ie. siRNA or chemicals, or activators have on STAT3 phosphorylation.
Dynamic Range:	> 5000 Cells
Detection Method:	Fluorometric
Storage/Stability:	4°C/6 Months
Reactivity:	Human, Mouse, Rat
Assay Type:	Cell-Based ELISA
Database Links:	Gene ID: 6774, UniProt ID: P40763, OMIM #: 102582/147060, Unigene #: Hs.463059
Format:	Two 96-Well Plates
NCBI Gene Symbol:	STAT3
Sub Type:	Phospho
Target Name:	Phospho-STAT3 (Ser727)

Kit Principle

Figure: Schematic representation of Assay Genie Cell-Based Fluorometric ELISA principle

Kit components	Quantity
96-Well Black Cell CultureClear-Bottom Microplate	2 plates
10X TBS	24 ml
Quenching Buffer	24 ml
Blocking Buffer	50 ml
15X Wash Buffer	50 ml
Primary Antibody Diluent	12 ml
100x Anti-Phospho Target Antibody	60 µl
100x Anti-Target Antibody	60 µl
Anti-GAPDH Antibody	110 µl
Dye-1 Conjugated Anti-Rabbit IgG Antibody	6 ml
Dye-2 Conjugated Anti-Mouse IgG Antibody	6 ml
Adhesive Plate Seals	2 seals

Additional equipment and materials required

The following materials and/or equipment are NOT provided in this kit but are necessary to successfully conduct the experiment:

Fluorescent plate reader with two channels at Ex/Em: 651/667 and 495/521
Micropipettes capable of measuring volumes from 1 µl to 1 ml
Deionized or sterile water (ddH2O)
37% formaldehyde (Sigma Cat# F-8775) or formaldehyde from other sources
Squirt bottle, manifold dispenser, multichannel pipette reservoir or automated microplate washer
Graph paper or computer software capable of generating or displaying logarithmic functions
Absorbent papers or vacuum aspirator
Test tubes or microfuge tubes capable of storing ≥1 ml
Poly-L-Lysine (Sigma Cat# P4832 for suspension cells)
Orbital shaker (optional)

Kit Protocol

This is a summarized version of the kit protocol. Please view the technical manual of this kit for information on sample preparation, reagent preparation and plate lay out.

1.	Seed 200 µl of desired cell concentration in culture medium into each well of the 96-well plates. For suspension cells and loosely attached cells, coat the plates with 100 µl of 10 µg/ml Poly-L-Lysine (not included) to each well of a 96-well plate for 30 minutes at 37°C prior to adding cells.
2.	Incubate the cells for overnight at 37°C, 5% CO2.
3.	Treat the cells as desired.
4.	Remove the cell culture medium and rinse with 200 µl of 1x TBS, twice.
5.	Fix the cells by incubating with 100 µl of Fixing Solution for 20 minutes at room temperature. The 4% formaldehyde is used for adherent cells and 8% formaldehyde is used for suspension cells and loosely attached cells.
6.	Remove the Fixing Solution and wash the plate 3 times with 200 µl 1x Wash Buffer for 3 minutes. The plate can be stored at 4°C for a week.
7.	Add 100 µl of Quenching Buffer and incubate for 20 minutes at room temperature.
8.	Wash the plate 3 times with 1x Wash Buffer for 3 minutes each time.
9.	Dispense 200 µl of Blocking Buffer and incubate for 1 hour at room temperature.
10.	Wash 3 times with 200 µl of 1x Wash Buffer for 3 minutes each time.
11.	Add 50 µl of Primary Antibody Mixture P to corresponding wells for STAT3 (Phospho-Ser727) detection. Add 50 µl of Primary Antibody Mixture NP to the corresponding wells for total STAT3 detection. Cover the plate with parafilm and incubate for 16 hours (overnight) at 4°C. If the target expression is known to be high, incubate for 2 hours at room temperature.
12.	Wash 3 times with 200 µl of 1x Wash Buffer for 3 minutes each time.
13.	Add 50 ul of Secondary Antibody Mixture to corresponding wells and incubate for 1.5 hours at room temperature in the dark.
14.	Wash 3 times with 200 µl of 1x Wash Buffer for 3 minutes each time.
15.	Read the plate(s) at Ex/Em: 651/667 (Dye 1) and 495/521 (Dye 2). Shield plates from direct light exposure.
16.	Wash 3 times with 200 µl of 1x Wash Buffer for 5 minutes each time.

STAT3 (Phospho-Ser727) - Protein Information

UniProt Protein Function:	STAT3: transcription factor of the STAT family. Phosphorylated and activated by receptor-associated kinases downstream of many cytokines and growth-factor receptors. Constitutively active in a number of human tumors. Forms homo- or heterodimers that translocate into the nucleus where they regulate transcription. Two alternatively spliced isoforms have been described.
UniProt Protein Details:	Protein type:Motility/polarity/chemotaxis; Nuclear receptor co-regulator; DNA-binding; Transcription factor Chromosomal Location of Human Ortholog: 17q21.31 Cellular Component: nucleoplasm; cytoplasm; mitochondrial inner membrane; plasma membrane; nucleus; cytosol Molecular Function:protein dimerization activity; ligand-dependent nuclear receptor activity; protein binding; signal transducer activity; DNA binding; sequence-specific DNA binding; protein phosphatase binding; transcription factor binding; protein kinase binding; transcription factor activity; glucocorticoid receptor binding; CCR5 chemokine receptor binding Biological Process: transcription from RNA polymerase II promoter; viral reproduction; nerve growth factor receptor signaling pathway; somatic stem cell maintenance; positive regulation of transcription, DNA-dependent; radial glial cell differentiation; negative regulation of transcription from RNA polymerase II promoter; thermoregulation; signal transduction; glucose homeostasis; response to estradiol stimulus; negative regulation of cell proliferation; regulation of transcription, DNA-dependent; astrocyte differentiation; protein import into nucleus; acute-phase response; negative regulation of glycolysis; positive regulation of Notch signaling pathway; response to drug; nervous system development; intracellular receptor-mediated signaling pathway; eating behavior; cytokine and chemokine mediated signaling pathway; regulation of multicellular organism growth; JAK-STAT cascade; cellular response to hormone stimulus; regulation of transcription from RNA polymerase II promoter; cell proliferation; response to ethanol; sexual reproduction; positive regulation of transcription from RNA polymerase II promoter; cell motility; eye photoreceptor cell differentiation; phosphorylation Disease: Hyper-ige Recurrent Infection Syndrome, Autosomal Dominant; Autoimmune Disease, Multisystem, Infantile-onset
NCBI Summary:	The protein encoded by this gene is a member of the STAT protein family. In response to cytokines and growth factors, STAT family members are phosphorylated by the receptor associated kinases, and then form homo- or heterodimers that translocate to the cell nucleus where they act as transcription activators. This protein is activated through phosphorylation in response to various cytokines and growth factors including IFNs, EGF, IL5, IL6, HGF, LIF and BMP2. This protein mediates the expression of a variety of genes in response to cell stimuli, and thus plays a key role in many cellular processes such as cell growth and apoptosis. The small GTPase Rac1 has been shown to bind and regulate the activity of this protein. PIAS3 protein is a specific inhibitor of this protein. Three alternatively spliced transcript variants encoding distinct isoforms have been described. [provided by RefSeq, Jul 2008]
UniProt Code:	P40763
NCBI GenInfo Identifier:	48429227
NCBI Gene ID:	6774
NCBI Accession:	P40763.2
UniProt Secondary Accession:	P40763,O14916, Q9BW54, A8K7B8, K7ENL3,
UniProt Related Accession:	P40763
Molecular Weight:	770
NCBI Full Name:	Signal transducer and activator of transcription 3
NCBI Synonym Full Names:	signal transducer and activator of transcription 3 (acute-phase response factor)
NCBI Official Symbol:	STAT3
NCBI Official Synonym Symbols:	APRF; HIES; ADMIO
NCBI Protein Information:	signal transducer and activator of transcription 3; DNA-binding protein APRF; acute-phase response factor
UniProt Protein Name:	Signal transducer and activator of transcription 3
UniProt Synonym Protein Names:	Acute-phase response factor
Protein Family:	Signal transducer and activator of transcription
UniProt Gene Name:	STAT3
UniProt Entry Name:	STAT3_HUMAN