Description
Histones are highly basic proteins that complex with DNA to form chromatin. Histone H3 is a ~15-kDa protein that is phosphorylated at serine 28 (S28), S10, and/or threonine 11 during mammalian cell mitosis and meiosis. The phosphorylation sites are located in the N-terminal tail, a region that is outside of the chromatin fiber and is thus accessible for interactions with agents that may regulate chromatin or specific gene activities. The phosphorylation states of the two serine sites during the cell cycle are highly regulated by Aurora B kinase and a PP1 phosphatase: S10 is in the phosphorylated state from late G2 phase to anaphase, while S28 is phosphorylated from prophase to anaphase. Furthermore, phosphorylation of histone H3 S28 may be mediated by other kinases in response to external stimuli. Evidence suggests that histone phosphorylation is involved in the regulation of chromosome condensation, cell division, and gene transcription. The HTA28 monoclonal antibody reacts with histone H3 phosphorylated at S28 in its N-terminal tail. It does not recognize the unphosphorylated protein.
1. Wash cell suspension twice with 1X PBS. 2. Fix the cells by adding ice-cold 70% ethanol drop-wise while vortexing the cell suspension, then storing them for at least 4 hours at -20°C in the 70% ethanol. 3. Aliquot ~1 million fixed cells per tube for staining. Wash them twice with 1X PBS, then once with stain buffer. 4. Stain the cells with 20 μl Alexa Fluor® 647 Rat anti-Histone H3 (pS28) in 80 μl stain buffer for 20 minutes at room temperature, then wash them with stain buffer. 5. For optimum cell cycle analysis, the cells should be treated with RNAse before staining with propidium iodide: • Treat the stained cells with 50 μg RNAse A (Sigma R5500) in 50 μl 1X PBS for 30 minutes at 37°C. Without washing, stain DNA by adding 5 μg Propidium Iodide (Sigma P4170) in 450 μl staining buffer for at least 10 minutes at room temperature. Or • Stain the cells with 0.5 ml PI/RNase Staining Buffer (Cat. No. 550825) for 15 minutes at room temperature. 6. The cells are now ready for flow cytometric analysis. BD™ CompBeads can be used as surrogates to assess fluorescence spillover (Compensation). When fluorochrome conjugated antibodies are bound to CompBeads, they have spectral properties very similar to cells. However, for some fluorochromes there can be small differences in spectral emissions compared to cells, resulting in spillover values that differ when compared to biological controls. It is strongly recommended that when using a reagent for the first time, users compare the spillover on cell and CompBead to ensure that BD Comp beads are appropriate for your specific cellular application.
Store undiluted at 4°C and protected from prolonged exposure to light. Do not freeze. The monoclonal antibody was purified from tissue culture supernatant or ascites by affinity chromatography. The antibody was conjugated to Alexa Fluor® 647 under optimum conditions, and unreacted Alexa Fluor® 647 was removed.
1. 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).
2. Alexa Fluor® 647 fluorochrome emission is collected at the same instrument settings as for allophycocyanin (APC).
3. For fluorochrome spectra and suitable instrument settings, please refer to our Multicolor Flow Cytometry web page at www.bdbiosciences.com/colors.
4. 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.
5. Source of all serum proteins is from USDA inspected abattoirs located in the United States.
6. Alexa Fluor® is a registered trademark of Molecular Probes, Inc., Eugene, OR.
7. The Alexa Fluor®, Pacific Blue™, and Cascade Blue® dye antibody conjugates in this product are sold under license from Molecular Probes, Inc. for research use only, excluding use in combination with microarrays, or as analyte specific reagents. The Alexa Fluor® dyes (except for Alexa Fluor® 430), Pacific Blue™ dye, and Cascade Blue® dye are covered by pending and issued patents.
8. This product is provided under an intellectual property license between Life Technologies Corporation and BD Businesses. The purchase of this product conveys to the buyer the non-transferable right to use the purchased amount of the product and components of the product in research conducted by the buyer (whether the buyer is an academic or for-profit entity). The buyer cannot sell or otherwise transfer (a) this product (b) its components or (c) materials made using this product or its components to a third party or otherwise use this product or its components or materials made using this product or its components for Commercial Purposes. Commercial Purposes means any activity by a party for consideration and may include, but is not limited to: (1) use of the product or its components in manufacturing; (2) use of the product or its components to provide a service, information, or data; (3) use of the product or its components for therapeutic, diagnostic or prophylactic purposes; or (4) resale of the product or its components, whether or not such product or its components are resold for use in research. For information on purchasing a license to this product for any other use, contact Life Technologies Corporation, Cell Analysis Business Unit Business Development, 29851 Willow Creek Road, Eugene, OR 97402, USA, Tel: (541) 465-8300. Fax: (541) 335-0504.
9. Please refer to http://regdocs.bd.com to access safety data sheets (SDS).
10. Species cross-reactivity detected in product development may not have been confirmed on every format and/or application.
11. Please refer to www.bdbiosciences.com/us/s/resources for technical protocols.
