Anti-cbx7 antibody - ChIP Grade (ab21873)

Reviews (7)Q&A (5)References (27)

Overview

  • Product name
    Anti-cbx7 antibody - ChIP Grade
    See all cbx7 primary antibodies
  • Description
    Rabbit polyclonal to cbx7 - ChIP Grade
  • Host species
    Rabbit
  • Tested applications
    Suitable for: ICC/IF, ChIP, WB, IHC-Pmore details
  • Species reactivity
    Reacts with: Mouse, Human
    Predicted to work with: Rat, Cow, Chimpanzee
  • Immunogen

    Synthetic peptide within Human cbx7 aa 200 to the C-terminus (C terminal) conjugated to keyhole limpet haemocyanin. The exact sequence is proprietary.
    Database link: O95931
    (Peptide available as ab22424)

  • Positive control
    • ab21873 gave a positive result in the following nuclear lysates: Hela, Jurkat, HepG2. This antibody gave a positive result in IHC in the following FFPE tissue: Human normal protate.

Properties

Applications

Our Abpromise guarantee covers the use of ab21873 in the following tested applications.

The application notes include recommended starting dilutions; optimal dilutions/concentrations should be determined by the end user.

Application Abreviews Notes
ICC/IF Use at an assay dependent concentration.
ChIP Use at an assay dependent concentration.
WB Use a concentration of 1 µg/ml. Detects a band of approximately 35 kDa (predicted molecular weight: 28 kDa).
IHC-P Use a concentration of 1 µg/ml.

Target

  • Relevance
    Control of cell proliferation by Polycomb group proteins (PcG) is an important facet of cellular homeostasis and its disruption can promote tumorigenesis. CBX7 is a novel PcG protein which is found to control the growth of normal cells. CBX7 is a gene that encodes a Polycomb protein, as shown by sequence homology, its interaction with Ring1 and its localization to nuclear Polycomb bodies. CBX7 extends the lifespan of a wide range of normal human cells and immortalizes mouse fibroblasts by downregulating expression of the Ink4a/Arf locus. CBX7 does not inter-function or colocalize with Bmi1, and both can exert their actions independently of each other as shown by reverse genetics. CBX7 was highly expressed in three different prostate cancer cell lines and present at elevated levels in normal prostate. (Gil et al., 2004).
  • Cellular localization
    Nuclear
  • Database links
    see all
  • Alternative names
    • Cbx 7 antibody
    • CBX7 antibody
    • Chromobox homolog 7 antibody
    • Chromobox protein homolog 7 antibody

Images

  • ChIP - Anti-cbx7 antibody - ChIP Grade (ab21873)
    ChIP - Anti-cbx7 antibody - ChIP Grade (ab21873)Image courtesy of an anonymous AbReview

    ab21873 was used at 1/100 dilution in cross-linking ChIP analysis of mouse mES E14 cells. Positive control: cbx7 overexpressing cells. Negative control: RA-treated cells.

    See Abreview

  • Western blot - Anti-cbx7 antibody - ChIP Grade (ab21873)
    Western blot - Anti-cbx7 antibody - ChIP Grade (ab21873)
    All lanes : Anti-cbx7 antibody - ChIP Grade (ab21873) at 1 µg

    Lane 1 : HeLa (Human epithelial carcinoma cell line) Nuclear Lysate
    Lane 2 : Jurkat nuclear extract lysate (ab14844)
    Lane 3 : HepG2 nuclear extract lysate (ab14660)

    Lysates/proteins at 10 µg per lane.

    Secondary
    All lanes : Goat polyclonal to Rabbit IgG - H&L - Pre-Adsorbed (HRP) at 1/3000 dilution

    Developed using the ECL technique.

    Performed under reducing conditions.

    Predicted band size: 28 kDa
    Observed band size: 34 kDa
    why is the actual band size different from the predicted?
    Additional bands at: 100 kDa, 70 kDa. We are unsure as to the identity of these extra bands.


    Exposure time: 30 seconds
  • Immunocytochemistry/ Immunofluorescence - Anti-cbx7 antibody - ChIP Grade (ab21873)
    Immunocytochemistry/ Immunofluorescence - Anti-cbx7 antibody - ChIP Grade (ab21873)Image courtesy of an Abreview submitted by Dr. Kirk McManus, Univ. of Manitoba/Cancer Care MICB, Canada
    ab21873 (1/1000) staining cbx7 in HeLa cells (green). Cells were fixed in paraformaldehyde, permeabilised with 0.5% Triton X-100/PBS and counterstained with DAPI in order to highlight the nucleus (red). For further experimental details please refer to Abreview.

    See Abreview

  • Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) - Anti-cbx7 antibody - ChIP Grade (ab21873)
    Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) - Anti-cbx7 antibody - ChIP Grade (ab21873)

    IHC image of cbx7 staining in Human normal prostate formalin fixed paraffin embedded tissue section, performed on a Leica BondTM system using the standard protocol F. The section was pre-treated using heat mediated antigen retrieval with sodium citrate buffer (pH6, epitope retrieval solution 1) for 20 mins. The section was then incubated with ab21873, 1µg/ml, for 15 mins at room temperature and detected using an HRP conjugated compact polymer system. DAB was used as the chromogen. The section was then counterstained with haematoxylin and mounted with DPX.

    For other IHC staining systems (automated and non-automated) customers should optimize variable parameters such as antigen retrieval conditions, primary antibody concentration and antibody incubation times.

  • Western blot - Anti-cbx7 antibody - ChIP Grade (ab21873)
    Western blot - Anti-cbx7 antibody - ChIP Grade (ab21873)
    All lanes : Anti-cbx7 antibody - ChIP Grade (ab21873) at 1 µg/ml

    Lane 1 : HeLa (Human epithelial carcinoma cell line) Whole Cell Lysate
    Lane 2 : HeLa (Human epithelial carcinoma cell line) Nuclear Lysate
    Lane 3 : Jurkat (Human T cell lymphoblast-like cell line) Whole Cell Lysate
    Lane 4 : Jurkat nuclear extract lysate (ab14844)
    Lane 5 : HepG2 (Human hepatocellular liver carcinoma cell line) Whole Cell Lysate
    Lane 6 : HepG2 nuclear extract lysate (ab14660)

    Lysates/proteins at 10 µg per lane.

    Secondary
    All lanes : Goat Polyclonal to rabbit IgG - H&L - Pre adsorbed (HRP) at 1/3000 dilution

    Performed under reducing conditions.

    Predicted band size: 28 kDa
    Observed band size: 34 kDa why is the actual band size different from the predicted?
    Additional bands at: 100 kDa, 70 kDa. We are unsure as to the identity of these extra bands.

References

This product has been referenced in:
  • Tatavosian R  et al. Live-cell single-molecule dynamics of PcG proteins imposed by the DIPG H3.3K27M mutation. Nat Commun 9:2080 (2018). Read more (PubMed: 29802243) »
  • Takeshita S  et al. Expression of P-REX2a is associated with poor prognosis in endometrial malignancies. Oncotarget 9:24778-24786 (2018). Read more (PubMed: 29872505) »
See all 27 Publications for this product

Publishing research using ab21873? Please let us know so that we can cite the reference in this datasheet.

Customer reviews and Q&As

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1-10 of 12 Abreviews or Q&A

Immunohistochemistry (Frozen sections) abreview for Anti-cbx7 antibody - ChIP Grade

 Excellent
Abreviews
abreview image
Application
Immunohistochemistry (Frozen sections)
Sample
Mouse Tissue sections (Skin)
Permeabilization
No
Specification
Skin
Blocking step
Serum as blocking agent for 30 minute(s) · Concentration: 10% · Temperature: 22°C
Fixative
Paraformaldehyde
Read More

Ahmar Aziz

Verified customer

Submitted Jul 08 2016

ChIP abreview for Anti-cbx7 antibody - ChIP Grade

 Excellent
Abreviews
abreview image
Application
ChIP
Sample
Mouse Cell lysate - nuclear (mES E14)
Negative control
RA treated cells
Specification
mES E14
Detection step
Real-time PCR
Type
Cross-linking (X-ChIP)
Duration of cross-linking step: 10 minute(s) and 0 second(s)
Specification of the cross-linking agent: PAF
Positive control
Cbx7 Overexpressing Cells
Read More

Abcam user community

Verified customer

Submitted Aug 12 2015

Western blot abreview for Anti-cbx7 antibody - ChIP Grade

 Excellent
Abreviews
abreview image
Application
Western blot
Sample
Mouse Cell lysate - whole cell (mES E14)
Gel Running Conditions
Reduced Denaturing
Loading amount
30 µg
Treatment
Retinoic Acid
Specification
mES E14
Blocking step
Milk as blocking agent for 30 minute(s) · Concentration: 10% · Temperature: 25°C
Read More

Abcam user community

Verified customer

Submitted Aug 12 2015

Question

I am interested in possibly using your CBX7 antibody (ab21873) in zebrafish. I was interested in this CBX7 antibody, in particular, since it seems have a more wide range of predicted species reactivity than your other CBX7 antibodies. I noticed that the epitope resides within 200 of the C-terminus of Human CBX7. What human CBX7 protein is this as there are three present in ensemble? My assumption is that it is CBX7-001 as it is the only protein > 200 amino acids.
Or, I have included the zebrafish CBX7 protein sequence below? Could you make any inferences about reactivity based on the % similarity of your product with the ZF protein?
Lastly, if you think this antibody would not be ideal, do any of your other CBX7 antibodies have more % similarity with the ZF protein?

Read More
Answer

Following up my previous message, the antibody ab123492 has not been tested for zebrafish reactivity and is unlikely to react, based on alignment of the immunogen with the zebrafish sequence you provided.
Please let us know if you have any other questions.

Read More

Question

I am interested in possibly using your CBX7 antibody (ab21873) in zebrafish. I was interested in this CBX7 antibody, in particular, since it seems have a more wide range of predicted species reactivity than your other CBX7 antibodies. I noticed that the epitope resides within 200 of the C-terminus of Human CBX7. What human CBX7 protein is this as there are three present in ensemble? My assumption is that it is CBX7-001 as it is the only protein > 200 amino acids.

Or, I have included the zebrafish CBX7 protein sequence below? Could you make any inferences about reactivity based on the % similarity of your product with the ZF protein?

Lastly, if you think this antibody would not be ideal, do any of your other CBX7 antibodies have more % similarity with the ZF protein?

Read More
Answer

The immunogen is derived from the human CBX7 at the following UniProt entry URL:

http://www.uniprot.org/uniprot/O95931 .

Alignment of the immunogen with the sequence provided gave poor results.
Unfortunately, alignments of the immunogens of three of four of our other antibodies against this protein were worse. I am waiting for the result for the fourth, ab123492, which I will send when I receive it.

Please do not hesitate to contact us if you need any more advice or information.

Read More

Immunocytochemistry/ Immunofluorescence abreview for Anti-cbx7 antibody - ChIP Grade

 Excellent
Abreviews
Abcam guarantees this product to work in the species/application used in this Abreview.
abreview image
Application
Immunocytochemistry/ Immunofluorescence
Sample
Human Cell (HeLa)
Specification
HeLa
Fixative
Paraformaldehyde
Permeabilization
Yes - 0.5% Triton-X100 in PBS
Read More

Dr. Kirk Mcmanus

Verified customer

Submitted Apr 18 2012

Question



Thanks for the generous offer. It was for two antibodies including two vials of Ab21873. Note that the order dates from 28/9/2010 and as I pointed out in my previous E-mail, we did receive replacements with an older batch. All I can say is that if lot number GR21097-1 works for chromatin immunoprecipitation, we will be happy to pay for it.

Read More
Answer

I have issued a free of charge replacement with the order number 1042072.

To check the status of the order please contact our Customer Service team and reference this number.

Please note that typically our Abpromise guarantee holds for 6 months from when you receive the antibody,although I have made an exception in this case.Should you still be experiencing difficulties, or if you have any further questions, please do not hesitate to let us know.

I wish you the best of luck with your research.

Read More

Question

Thank you for the offer of a replacement vial. However, I suspect that the previous "complaint" you refer to came from us and Abcam kindly replaced the antibody with an earlier batch. I don't think we should expect more.



My question, which was simply prompted by an E-mail from Abcam, was whether there is now a more recent batch of ab21873 (presumably lot GR21097-1) and if so, would it be possible for us to test an aliquot in ChIP conditions before buying several vials.

Read More
Answer

Thanks for your reply.

You are correct that lot GR21097-1 is a new lot we have in stock. We are not able to stock small sample aliqots of our antibodies unfortunately. However, since a vial of ab21873 you previously purchased is not working as expected,I can provide you with a free replacement vial of this new lot based on our Abpromise guarantee https://www.abcam.com/abpromise

If you would like to go ahead with the replacement offer, please just provide me with the PO number or Abcam order reference number associated with the purchase of ab21873, lot 937205 so I can process the replacement.

Read More

Question


As it happens, we have been having some issues with batch-to-batch
variation with an antibody against CBX7 (AB21873) that we use extensively
for chromatin immunoprecipitation (ChIP). Lot # 937204 worked very well
whereas Lot #937205 did not. We did manage to get what we believe may
have been the last aliquots of the good batch but are just about to run
out. If there have been any more recent batches, we would be very keen to
try some before restocking.

Read More
Answer

Thank you for your enquiry. I am sorry to hear of the trouble you are having with lot 937205 in ChIP. I looked in our records and there was one other complaint of a similar nature regarding ChIP with this lot of ab21873. We do have a new lot in stock now (lot GR21097-1) and I am happy to offer a replacement for the faulty vial of ab21873.

Please pass along the PO number or Abcam order reference number associated with the purchase of ab21873, lot 937205 so I can process the replacement.

Read More

ChIP abreview for Anti-cbx7 antibody - ChIP Grade

 Excellent
Abreviews
Abcam guarantees this product to work in the species/application used in this Abreview.
abreview image
Application
ChIP
Sample
Mouse Cell lysate - whole cell (mouse embryonic stem cells)
Specification
mouse embryonic stem cells
Type
Cross-linking (X-ChIP)
Duration of cross-linking step: 10 minute(s) and 0 second(s)
Specification of the cross-linking agent: formaldehyde
Detection step
Real-time PCR
Positive control
Polycomb targets
Negative control
Ensa, B2M, RPS14 genes
Read More

Dr. Ligia Tavares

Verified customer

Submitted Sep 23 2011

1-10 of 12 Abreviews or Q&A

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