|Application||WB, IHC, IF,ELISA|
|Reactivity||Human Mouse Rat|
|Storage buffer||10 mM sodium HEPES (pH 7.5), 150 mM NaCl, 100 µg/ml BSA, 50% glycerol and less than 0.02% sodium azide.|
|Storage||Store at –20°C.|
1. Aspirate media from cultures and Wash the cells with 1X PBS. 2. Lyse cells by adding 1X SDS sample buffer and transfer the extract to a microcentrifuge tube. Keep onice. 3. Sonicate for 10–15 sec to complete cell lysis and shear DNA. 4. Heat a 20 µl sample to 95–100°C for 5 min, then cool on ice. 5. Centrifuge for 5 min (with Microcentrifuge). 6. Load appropriate volumes of samples onto SDS-PAGE gel (loading quantity of protein sample depends on the concentration of extracted proteins). NOTE: At the same time, please load the pre-stained molecular weight markers to determine molecular weights and verify electrotransfer. 7. Electrotransfer to nitrocellulose/PVDF membrane.
Membrane Blocking and Antibody Incubations
1. (Optional) After transfer, wash the transferred membrane with TBS for 5 min at room temperature. 2. Incubate the membrane in the blocking buffer for 1 hr at room temperature. 3. Wash three times for 5 min each with TBST.
b. Antibodies Incubation
1. Incubate membrane and primary antibody (at the appropriate dilution and diluent recommended) in a primary antibody dilution buffer with gentle agitation overnight at 4°C. 2. Wash three times for 5 min each with TBST. 3. Incubate membrane with an appropriate second antibodydissolved in the blocking buffer with gentle agitation for 1 hr at room temperature. 4. Wash three times for 5 min each with TBST. 5. Proceed with detection.
Detection of Proteins
1. After antibodies incubation, Wash membrane three times for 5 minutes in TBST. 2. PrepareECL Reagent (or other chromogenic agents/substrate according to your second antibody). Mix well. 3. Incubate substrate with membrane for 1 minute, remove excess solution (membrane remains wet), wrap in plastic and expose to X-ray film.
NOTE: Do not allow slides to dry at any time during this procedure.
1. Deparaffinize/hydrate sections:
1. Incubate sections in three washes of xylene for 5 min each.
2. Wash sections two times in dH2O for 5 min each.
For Citrate: Heat slides in a microwave submersed in 1X citrate unmasking solution until boiling is initiated; continue with 10 min at a sub-boiling temperature (95°-98°C). Cool slides on bench top for 30 min.
1. Wash sections in dH2O three times for 5 min each.
Specimen Preparation (forcultured cell lines, IF-IC)
1. Aspirate liquid, then cover cells to a depth of 2–3 mm with 4% formaldehyde diluted in 1X PBS.
1. Add theblocking buffer and incubate for 60 min at RT.
STAT2 Antibody detects endogenous levels of STAT2.
STAT proteins are critical for transmitting information from many different transmembrane surface receptors, such as cytokine and hormone receptors, to the nucleus. The STAT family contains seven members (STAT1-6 including STAT5A and STAT5B) all of which share the same overall domain architecture: an N-terminal domain (ND), a coiled-coil domain (CCD), a DNA-binding domain (DBD), a linker domain (LD), a Src homology 2 (SH2) domain, and a transactivation domain (TAD). STATs are activated by phosphorylation of a conserved tyrosine performed by one or more receptor-associated tyrosine kinases from the Janus family of tyrosine kinases named JAK. Tyrosine phosphorylation results in reciprocal binding of one phosphorylated STAT to another, forming either a homodimer or a heterodimer. In the nucleus, the STAT-dimer binds the promoter of genes and either induce or repress mRNA expression. STAT2 is defined as a co-factor only involved in type I IFN (IFN-α, -β, -τ, -ω) signaling, as compared with STAT1, which is found to be important in additional cytokine-induced signaling pathways, such as IFN-γ, IL-4, IL-6, and IL-27 to name a few examples.