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- Additional protein information
- Analytical tools
Phospho-Rb (Ser807/811) (D20B12) XP® Rabbit mAb (Alexa Fluor® 555 Conjugate) #8957
Confocal immunofluorescent analysis of MCF7 cells, untreated (left) or λ phosphatase-treated (middle), and BT-549 cells (right), using Phospho-Rb (Ser807/811) (D20B12) XP® Rabbit mAb (Alexa Fluor® 555 Conjugate) (red). Actin filaments were labeled with Alexa Fluor® 488 phalloidin (green).Learn more about how we get our images
Flow cytometric analysis of BT-549 cells (blue) and Jurkat cells (green) using Phospho-Rb (Ser807/811) (D20B12) XP® Rabbit mAb (Alexa Fluor® 555 Conjugate) (solid lines) or a concentration-matched Rabbit (DA1E) mAb IgG XP® Isotype Control (Alexa Fluor® 555 Conjugate) #3969 (dashed lines)Learn more about how we get our images
Gallery: Phospho-Rb (Ser807/811) (D20B12) XP® Rabbit mAb (Alexa Fluor® 555 Conjugate) #8957
A. Solutions and Reagents
NOTE: Prepare solutions with reverse osmosis deionized (RODI) or equivalently purified water.
- 20X Phosphate Buffered Saline (PBS): (9808) To prepare 1L 1X PBS: add 50 ml 20X PBS to 950 ml dH2O, mix. Adjust pH to 8.0.
- Formaldehyde: 16%, methanol free, Polysciences, Inc. (cat# 18814), use fresh and store opened vials at 4°C in dark, dilute in 1X PBS for use.
- Permeabilization Buffer (1X PBS/0.2% Triton X-100):
To prepare 25 ml, add 2.5 ml 10X PBS, and 22.5 ml dH2O and mix well. While stirring, add 50 µl Triton X-100.
- Image-iT™ FX Signal Enhancer (#11932)
- Blocking Buffer (1X PBS / 5% normal serum / 0.3% Triton™ X-100): To prepare 10 ml, add 0.5 ml normal serum from the same species as the secondary antibody (e.g., Normal Goat Serum (#5425)) and 0.5 mL 20X PBS to 9.0 mL dH2O, mix well. While stirring, add 30 µl Triton™ X-100.
- Antibody Dilution Buffer (1X PBS / 1% BSA / 0.3% Triton X-100): To prepare 10 ml, add 30 µl Triton™ X-100 to 10 ml 1X PBS. Mix well then add 0.1 g BSA (9998), mix.
- Prolong® Gold AntiFade Reagent (#9071), Prolong® Gold AntiFade Reagent with DAPI (#8961).
B. Specimen Preparation - Cultured Cell Lines (IF-IC)
NOTE: Cells should be grown, treated, fixed, and stained directly in multi-well plates, chamber slides, or on coverslips.
- Aspirate liquid, then cover cells to a depth of 2–3 mm with 4% formaldehyde in 1X PBS.
NOTE: Formaldehyde is toxic, use only in fume hood.
- Allow cells to fix for 15 minutes at room temperature.
- Aspirate fixative, rinse three times in 1X PBS for 5 minutes each.
- Proceed with Immunostaining (Section C).
NOTE: All subsequent incubations should be carried out at room temperature unless otherwise noted in a humid light-tight box or covered dish/plate to prevent drying and fluorochrome fading.
- Permeabilize the cells in Permeabilization Buffer for 5 minutes at room temperature.
- Rinse three times in 1X PBS for 5 minutes each.
- Apply 3–4 drops of Image-iT™ FX Signal Enhancer (#11932) and incubate for 30 minutes at room temperature.
- Rinse three times with 1X PBS for 5 minutes each.
- Block specimen in Blocking Buffer for 60 minutes.
- While blocking, prepare primary antibody by diluting as indicated on datasheet in Antibody Dilution Buffer.
- Aspirate blocking solution, apply diluted primary antibody.
- Incubate overnight at 4°C.
- Rinse three times in 1X PBS for 5 minutes each.
- Coverslip slides with Prolong® Gold Antifade Reagent (#9071), Prolong® Gold AntiFade Reagent with DAPI (#8961).
- For best results, examine specimens immediately using appropriate excitation wavelength. For long-term storage, store slides flat at 4°C protected from light.
posted Februay 2011
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-Rb (Ser807/811) (D20B12) XP® Rabbit mAb (Alexa Fluor® 555 Conjugate) recognizes endogenous levels of Rb protein only when phosphorylated at Ser807, Ser811, or at both sites. This antibody does not cross-react with Rb phosphorylated at Ser608.Species Reactivity: Human, Mouse, Rat, Monkey
Monoclonal antibody is produced by immunizing animals with a synthetic phosphopeptide corresponding to residues surrounding Ser807/811 of human Rb protein.
This Cell Signaling Technology antibody is conjugated to Alexa Fluor® 555 fluorescent dye and tested in-house for direct flow cytometry and immunofluorescent analysis in human cells. The antibody is expected to exhibit the same species cross-reactivity as the unconjugated Phospho-Rb (Ser807/811) (D20B12) XP® Rabbit mAb #8516.
The retinoblastoma tumor suppressor protein Rb regulates cell proliferation by controlling progression through the restriction point within the G1-phase of the cell cycle (1). Rb has three functionally distinct binding domains and interacts with critical regulatory proteins including the E2F family of transcription factors, c-Abl tyrosine kinase, and proteins with a conserved LXCXE motif (2-4). Cell cycle-dependent phosphorylation by a CDK inhibits Rb target binding and allows cell cycle progression (5). Rb inactivation and subsequent cell cycle progression likely requires an initial phosphorylation by cyclin D-CDK4/6 followed by cyclin E-CDK2 phosphorylation (6). Specificity of different CDK/cyclin complexes has been observed in vitro (6-8) and cyclin D1 is required for Ser780 phosphorylation in vivo (9).
For Research Use Only. Not For Use In Diagnostic Procedures. Cell Signaling Technology is a 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.