• Product name
    Anti-RAX antibody
  • Description
    Rabbit polyclonal to RAX
  • Host species
  • Specificity
    ab23340 reacts with RAX (retinal homeobox protein Rx).
  • Tested applications
    Suitable for: IHC-P, WBmore details
  • Species reactivity
    Reacts with: Human
    Predicted to work with: Mouse, Rat, Cow
  • Immunogen

    Synthetic peptide corresponding to Human RAX aa 1-50.


    Database link: Q9Y2V3

  • Positive control
    • Jurkat whole cell lysate (ab7899)


  • Form
  • Storage instructions
    Shipped at 4°C. Upon delivery aliquot and store at -20°C. Avoid freeze / thaw cycles.
  • Storage buffer
    Preservative: 0.09% Sodium azide
    Constituents: 2% Sucrose, PBS
  • Concentration information loading...
  • Purity
    Immunogen affinity purified
  • Clonality
  • Isotype
  • Research areas


Our Abpromise guarantee covers the use of ab23340 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
IHC-P Use at an assay dependent concentration.
WB Use a concentration of 0.2 - 5 µg/ml. Detects a band of approximately 32 kDa (predicted molecular weight: 38 kDa). Good results were obtained when blocked with 5% non-fat dry milk in 0.05% PBS-T.


  • Function
    Plays a critical role in eye formation by regulating the initial specification of retinal cells and/or their subsequent proliferation. Binds to the photoreceptor conserved element-I (PCE-1/Ret 1) in the photoreceptor cell-specific arrestin promoter.
  • Tissue specificity
    Expressed in the developing eye and weakly expressed in the adult retina.
  • Involvement in disease
    Defects in RAX are the cause of microphthalmia isolated type 3 (MCOP3) [MIM:611038]. Microphthalmia is a clinically heterogeneous disorder of eye formation, ranging from small size of a single eye to complete bilateral absence of ocular tissues. Ocular abnormalities like opacities of the cornea and lens, scaring of the retina and choroid, cataractand other abnormalities like cataract may also be present.
  • Sequence similarities
    Belongs to the paired homeobox family. Bicoid subfamily.
    Contains 1 homeobox DNA-binding domain.
  • Cellular localization
  • Information by UniProt
  • Database links
  • Alternative names
    • MCOP3 antibody
    • RAX antibody
    • retina and anterior neural fold homeobox antibody
    • Retina and anterior neural fold homeobox protein antibody
    • Retinal homeobox protein Rx antibody
    • RX antibody
    • RX_HUMAN antibody
    see all


  • Anti-RAX antibody (ab23340) at 1 µg/ml + Jurkat cell lysate

    Performed under reducing conditions.

    Predicted band size: 38 kDa
    Observed band size: 32 kDa
    why is the actual band size different from the predicted?

  • ab23340 at 4.0 µg/ml staining human spermatophore by IHC-P.  Epithelial cells, with positive label, are indicated with arrows. Magnification 400X.


ab23340 has not yet been referenced specifically in any publications.

Customer reviews and Q&As

1-2 of 2 Abreviews or Q&A

Abcam has not validated the combination of species/application used in this Abreview.
Immunocytochemistry/ Immunofluorescence
Mouse Cell (retina)
Yes - 0.2% triton x-100
Blocking step
Serum as blocking agent for 1 hour(s) and 0 minute(s) · Concentration: 5% · Temperature: RT°C

Abcam user community

Verified customer

Submitted Oct 18 2017


Thank you for your enquiry and for your patience. It has taken some time to discuss this with our source for this antibody.

It is unfortunately difficult to say what the lighter brown staining is exactly in the IHC image provided for ab23340. A western blot with this tissue (human spermatophore epithelial cells) would have to be run to determine if any non-specific staining is there. As this protein (RAX) is a transcription factor, and this IHC image includes the nuclear stain, DAPI, the brown/blue staining is the specific signal here. The lighter brown is cytosolic staining, which could be non specific. It may be the experiment required further optimization in this case and I am sorry we have no further information on this occasion as it has been tested externally.

Regarding EMX1 antibodies, we have several available. However, I am sorry that regrettably non of these have been tested in IHC-Fr (cryosections).

ab32925 Emx1 antibody
Rabbit polyclonal
Reacts with: Rat
Please note this is a fast track antibody which has not yet been fully characterised. Further information on the terms and conditions for using Fast Track antibodies can be found from the datasheet:
https://www.abcam.com/index.html?datasheet=32925 https://www.abcam.com/index.html?datasheet=32925.

ab82901 Emx1 antibody
Rabbit polyclonal
Tested in: WB
Reacts with: Human
https://www.abcam.com/index.html?datasheet=82901 https://www.abcam.com/index.html?datasheet=82901.

ab125443 Anti-Emx1 antibody
Rabbit polyclonal
Tested in: WB
Reacts with: Mouse
https://www.abcam.com/index.html?datasheet=125443 https://www.abcam.com/index.html?datasheet=125443.

If you would like to test one of the non Fast Track antibodies in this untested application, please do not hestitate to contact me again prior to the purchase by replying to this message as you may be eligible for our testing discount program.

Otherwise, we like to encourage all of our customers to submit an Abreview via the online product datasheet. We always appreciate customer feedback, whether positive or negative, and we make all product information available to researchers. Plus, each Abreview earns Abpoints that can be used for discounts on future purchases or rewards such as Amazon.com gift certificates.

To find out more about our Abreview system, please see the following link:

I hope this information is helpful. Please do not hesitate to contact me for any further advice or information.

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