Revision 3

#9309Store at -20C

Cell Signaling Technology

Orders: 877-616-CELL (2355) [email protected]

Support: 877-678-TECH (8324)

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3 Trask LaneDanversMassachusetts01923USA
For Research Use Only. Not for Use in Diagnostic Procedures.



H Mk B Pg



MW (kDa):



Mouse IgG2a

UniProt ID:


Entrez-Gene Id:


Product Information

Product Usage Information

For optimal ChIP results, use 5 μl of antibody and 10 μg of chromatin (approximately 4 x 106 cells) per IP. This antibody has been validated using SimpleChIP® Enzymatic Chromatin IP Kits.

Application Dilution
Western Blotting 1:2000
Immunoprecipitation 1:100
Immunohistochemistry (Paraffin) 1:400 - 1:1600
Immunofluorescence (Immunocytochemistry) 1:800 - 1:3200
Flow Cytometry (Fixed/Permeabilized) 1:200 - 1:800
Chromatin IP 1:200


Supplied in 10 mM sodium HEPES (pH 7.5), 150 mM NaCl, 100 µg/ml BSA, 50% glycerol and less than 0.02% sodium azide. Store at –20°C. Do not aliquot the antibody.

For a carrier-free (BSA and azide free) version of this product see product #61121.

Specificity / Sensitivity

Rb (4H1) Mouse mAb detects endogenous levels of total Rb protein. The antibody does not cross-react with the Rb homologues p107 or p130, or with other proteins.

Species Reactivity:

Human, Monkey, Bovine, Pig

Source / Purification

Monoclonal antibody is produced by immunizing animals with a Rb-C fusion protein containing residues 701-928 of human Rb. The epitope corresponds to a region surrounding His890 of human Rb.


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).

  1. Sherr, C.J. (1996) Science 274, 1672-7.
  2. Nevins, J.R. (1992) Science 258, 424-9.
  3. Welch, P.J. and Wang, J.Y. (1993) Cell 75, 779-90.
  4. Hu, Q.J. et al. (1990) EMBO J 9, 1147-55.
  5. Knudsen, E.S. and Wang, J.Y. (1997) Mol Cell Biol 17, 5771-83.
  6. Lundberg, A.S. and Weinberg, R.A. (1998) Mol Cell Biol 18, 753-61.
  7. Connell-Crowley, L. et al. (1997) Mol Biol Cell 8, 287-301.
  8. Kitagawa, M. et al. (1996) EMBO J 15, 7060-9.
  9. Geng, Y. et al. (2001) Proc Natl Acad Sci USA 98, 194-9.

Species Reactivity

Species reactivity is determined by testing in at least one approved application (e.g., western blot).

Western Blot Buffer

IMPORTANT: For western blots, incubate membrane with diluted primary antibody in 5% w/v nonfat dry milk, 1X TBS, 0.1% Tween® 20 at 4°C with gentle shaking, overnight.

Applications Key

WB: Western Blotting IP: Immunoprecipitation IHC-P: Immunohistochemistry (Paraffin) IF-IC: Immunofluorescence (Immunocytochemistry) FC-FP: Flow Cytometry (Fixed/Permeabilized) ChIP: Chromatin IP

Cross-Reactivity Key

H: human M: mouse R: rat Hm: hamster Mk: monkey Vir: virus Mi: mink C: chicken Dm: D. melanogaster X: Xenopus Z: zebrafish B: bovine Dg: dog Pg: pig Sc: S. cerevisiae Ce: C. elegans Hr: horse GP: Guinea Pig Rab: rabbit All: all species expected

Trademarks and Patents

Cell Signaling Technology is a trademark of Cell Signaling Technology, Inc.
Alexa Fluor is a registered trademark of Life Technologies Corporation.
All other trademarks are the property of their respective owners. Visit for more information.

Limited Uses

Except as otherwise expressly agreed in a writing signed by a legally authorized representative of CST, the following terms apply to Products provided by CST, its affiliates or its distributors. Any Customer's terms and conditions that are in addition to, or different from, those contained herein, unless separately accepted in writing by a legally authorized representative of CST, are rejected and are of no force or effect.

Products are labeled with For Research Use Only or a similar labeling statement and have not been approved, cleared, or licensed by the FDA or other regulatory foreign or domestic entity, for any purpose. Customer shall not use any Product for any diagnostic or therapeutic purpose, or otherwise in any manner that conflicts with its labeling statement. Products sold or licensed by CST are provided for Customer as the end-user and solely for research and development uses. Any use of Product for diagnostic, prophylactic or therapeutic purposes, or any purchase of Product for resale (alone or as a component) or other commercial purpose, requires a separate license from CST. Customer shall (a) not sell, license, loan, donate or otherwise transfer or make available any Product to any third party, whether alone or in combination with other materials, or use the Products to manufacture any commercial products, (b) not copy, modify, reverse engineer, decompile, disassemble or otherwise attempt to discover the underlying structure or technology of the Products, or use the Products for the purpose of developing any products or services that would compete with CST products or services, (c) not alter or remove from the Products any trademarks, trade names, logos, patent or copyright notices or markings, (d) use the Products solely in accordance with CST Product Terms of Sale and any applicable documentation, and (e) comply with any license, terms of service or similar agreement with respect to any third party products or services used by Customer in connection with the Products.

Revision 3

Rb (4H1) Mouse mAb

Western Blotting Image 1: Rb (4H1) Mouse mAb Expand Image
Western blot analysis of extracts from HeLa cells (lane 1) or Rb knock-out cells (lane 2) using Rb (4H1) Mouse mAb #9309 (upper), and β-actin (D6A8) Rabbit mAb #8457 (lower). The absence of signal in the Rb knock-out HeLa cells confirms specificity of the antibody for Rb.
Western Blotting Image 2: Rb (4H1) Mouse mAb Expand Image
Western blot analysis of extracts from HeLa cells, transfected with 100 nM SignalSilence® Control siRNA (Fluorescein Conjugate) #6201 (-), SignalSilence® Rb siRNA I #6451 (+) or SignalSilence® Rb siRNA II (+), using Rb (4H1) Mouse mAb #9309 and α-Tubulin (11H10) Rabbit mAb #2125. The Rb (4H1) Mouse mAb confirms silencing of Rb expression, while the α-Tubulin (11H10) Rabbit mAb is used to control for loading and specificity of Rb siRNA.
Western Blotting Image 3: Rb (4H1) Mouse mAb Expand Image
Western blot analysis of extracts from COS-7 cells, untreated or hydroxyurea-treated (G1/S), using Rb (4H1) Mouse mAb.
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Immunohistochemistry Image 1: Rb (4H1) Mouse mAb Expand Image
Immunohistochemical analysis of paraffin-embedded human breast carcinoma, showing nuclear localization, using Rb (4H1) Mouse mAb.
Immunohistochemistry Image 2: Rb (4H1) Mouse mAb Expand Image
Immunohistochemical analysis of paraffin-embedded human lung carcinoma, using Rb (4H1) Mouse mAb.
Immunohistochemistry Image 3: Rb (4H1) Mouse mAb Expand Image
Immunohistochemical analysis of paraffin-embedded human esophageal carcinoma using Rb (4H1) Mouse mAb.
Immunohistochemistry Image 4: Rb (4H1) Mouse mAb Expand Image
Immunohistochemical analysis of paraffin-embedded human T cell lymphoblastic lymphoma using Rb (4H1) Mouse mAb.
Immunohistochemistry Image 5: Rb (4H1) Mouse mAb Expand Image
Immunohistochemical analysis of paraffin-embedded human gastric adenocarcinoma using Rb (4H1) Mouse mAb.
Immunofluorescence Image 1: Rb (4H1) Mouse mAb Expand Image
Confocal immunofluorescent image of SH-SY5Y cells, using RB (4H1) Mouse mAb (green). Actin filaments have been labeled with Alexa Fluor® 555 phalloidin (red).
Flow Cytometry Image 1: Rb (4H1) Mouse mAb Expand Image
Flow cytometric analysis of Jurkat cells, using Rb (4H1) Mouse mAb versus propidium iodide (DNA content). The box indicates Rb positive cells.
Chromatin Immunoprecipitation Image 1: Rb (4H1) Mouse mAb Expand Image
Chromatin immunoprecipitations were performed with cross-linked chromatin from Raji cells and either Rb (4H1) Mouse mAb or Normal Rabbit IgG #2729 using SimpleChIP® Enzymatic Chromatin IP Kit (Magnetic Beads) #9003. The enriched DNA was quantified by real-time PCR using using SimpleChIP® Human Timeless Intron 1 Primers #7001, human DHFR promoter primers, and SimpleChIP® Human α Satellite Repeat Primers #4486. The amount of immunoprecipitated DNA in each sample is represented as signal relative to the total amount of input chromatin, which is equivalent to one.