Description
Stat (Signal transducer and activators of transcription) proteins mediate the biological activity of cytokines, including interleukins, interferons, erythropoietin, and growth factors. Ligand-receptor interaction activates constitutively-associated JAK family kinases as well as subsequent recruitment and activation of Stat proteins by tyrosine phosphorylation. Active Stat proteins then move to the nucleus to promote transcription of cytokine-inducible genes. Seven Stat proteins have been cloned, each of which is differentially expressed and/or activated in a cytokine-specific and cell type-specific manner. Stat1 and Stat2 are components of the ISGF3 (Interferon-Stimulated Gene Factor 3) complex, the primary transcription activator induced by interferon binding to a specific cell-surface receptor. Stat1 has two alternatively spliced isoforms, 91-kDa Stat1α and 84-kDa Stat1β; Stat1α has 38 additional C-terminal amino acids. In response to the binding of IFNα, IFNγ, EGF, PDGF, or CSF-1 to their respective receptors, the Stat1 subunits become tyrosine-phosphorylated at Y701, and the complex translocates to the nucleus. This forms an active complex that includes the DNA-binding p48 subunit, and is responsible for modulating interferon-stimulated genes (ISGs) transciption.
The 4a monoclonal antibody recognizes the phosphorylated Y701 in Stat1α and Stat1β.
Format
- Format
PerCP-Cy™5.5
- Excitation Source
Blue 488 nm
- Excitation Max
482 nm
- Emission Max
678 nm
PerCP-Cy™5.5 is a tandem conjugate that combines PerCP with a cyanine dye. PerCP-Cy5.5 is not subject to photobeaching like PerCP and can be used with stream-in-air flow cytometers. It has less Fc receptor–mediated nonspecific staining than PE-Cy5. Additionally, the PerCP-Cy5.5 tandem conjugate is not as susceptible to fixative or light instability compared to APC-Cy7 and PE-Cy7.
Suggested Companion Products
Preparation and Storage
The monoclonal antibody was purified from tissue culture supernatant or ascites by affinity chromatography.
The antibody was conjugated with PerCP-Cy5.5 under optimum conditions, and unconjugated antibody and free PerCP-Cy5.5 were removed. Storage of PerCP-Cy5.5 conjugates in unoptimized diluent is not recommended and may result in loss of signal intensity.
Store undiluted at 4°C and protected from prolonged exposure to light. Do not freeze.
Product Notices
- This reagent has been pre-diluted for use at the recommended Volume per Test. We typically use 1 × 10^6 cells in a 100-µl experimental sample (a test).
- Please observe the following precautions: Absorption of visible light can significantly alter the energy transfer occurring in any tandem fluorochrome conjugate; therefore, we recommend that special precautions be taken (such as wrapping vials, tubes, or racks in aluminum foil) to prevent exposure of conjugated reagents, including cells stained with those reagents, to room illumination.
- PerCP-Cy5.5–labelled antibodies can be used with FITC- and R-PE–labelled reagents in single-laser flow cytometers with no significant spectral overlap of PerCP-Cy5.5, FITC, and R-PE fluorescence.
- PerCP-Cy5.5 is optimized for use with a single argon ion laser emitting 488-nm light. Because of the broad absorption spectrum of the tandem fluorochrome, extra care must be taken when using dual-laser cytometers, which may directly excite both PerCP and Cy5.5™. We recommend the use of cross-beam compensation during data acquisition or software compensation during data analysis.
- This product is subject to proprietary rights of Amersham Biosciences Corp. and Carnegie Mellon University and made and sold under license from Amersham Biosciences Corp. This product is licensed for sale only for research. It is not licensed for any other use. If you require a commercial license to use this product and do not have one return this material, unopened to BD Biosciences, 10975 Torreyana Rd, San Diego, CA 92121 and any money paid for the material will be refunded.
- Cy is a trademark of Amersham Biosciences Limited. This conjugated product is sold under license to the following patents: US Patent Nos. 5,486,616; 5,569,587; 5,569,766; 5,627,027.
- Caution: Sodium azide yields highly toxic hydrazoic acid under acidic conditions. Dilute azide compounds in running water before discarding to avoid accumulation of potentially explosive deposits in plumbing.
- Source of all serum proteins is from USDA inspected abattoirs located in the United States.
- For fluorochrome spectra and suitable instrument settings, please refer to our Multicolor Flow Cytometry web page at www.bdbiosciences.com/colors.
- Please refer to www.bdbiosciences.com/us/s/resources for technical protocols.
Either BD Cytofix™ fixation buffer or BD Phosflow™ Fix Buffer I may be used for cell fixation.
This mAb was characterized by flow cytometry (Flow) and western blot analysis (WB) using these model systems:
Method Species Cells Treatment Fixation Perm buffer Result
Flow Human PBMC IFNγ Fixation Buffer III Positive Staining
Flow Human PBMC IFNγ Fixation Buffer I or II Unsatisfactory
WB Human U937 Cell Lysate IFNγ Not Applicable Not Applicable 91/84 kDa
WB Human A431 Cell Lysate EGF Not Applicable Not Applicable 91/84 kDa
