• Product name

    Anti-HLA-DP antibody [B7/21]
    See all HLA-DP primary antibodies
  • Description

    Mouse monoclonal [B7/21] to HLA-DP
  • Host species

  • Specificity

    This antibody recognizes the human major histocompatibility complex (MHC) class II protein HLA-DP, which consists of an alpha and beta chain. MHC Class II (HLA-DP) is expressed on antigen-presenting cells (APCs) including B cells, dendritic cells, Langerhans cells and macrophages. It is also expressed by activated human T cells. HLA-DP initiates immune responses by presenting extracellular antigens to CD4+ T cells. The B7/21 clone recognizes HLA-DP1, DP2, DP3, DP4 and DP5 and recognizes both the alpha and beta chains (PubMed IDs 3494718 and 6192342).
  • Tested applications

    Suitable for: Flow Cyt, Inhibition Assay, ICC/IFmore details
  • Species reactivity

    Reacts with: Mouse, Human
  • Immunogen

    The details of the immunogen for this antibody are not available.

  • Positive control

    • IF/ICC: Raw 246.7 cells.
  • General notes

    This antibody clone is manufactured by Abcam.

    If you require this antibody in a particular buffer formulation or a particular conjugate for your experiments, please contact orders@abcam.com or you can find further information here.


  • Form

  • Storage instructions

    Shipped at 4°C. Store at +4°C.
  • Storage buffer

    pH: 7.40
    Preservative: 0.02% Sodium azide
    Constituents: PBS, 6.97% L-Arginine
  • Concentration information loading...
  • Purity

    Protein A purified
  • Clonality

  • Clone number

  • Isotype

  • Research areas


Our Abpromise guarantee covers the use of ab20897 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
Flow Cyt Use 1µg for 106 cells.
Inhibition Assay Use at an assay dependent concentration. PubMed: 19531622
ICC/IF Use a concentration of 5 µg/ml.


  • Relevance

    HLA-DPA1 belongs to the HLA class II alpha chain paralogues. This class II molecule is a heterodimer consisting of an alpha (DPA) and a beta (DPB) chain, both anchored in the membrane. It plays a vital role in the immune system by presenting peptides derived from extracellular proteins. Class II molecules are expressed in antigen presenting cells (B lymphocytes, dendritic cells and macrophages). Within the DP molecule the alpha and beta chain contain the polymorphisms governing the peptide binding specificities, resulting in up to 4 different molecules.
  • Cellular localization

    Type I membrane protein; Cell Membrane, Endoplasmic reticulum and Golgi Apparatus
  • Database links

  • Alternative names

    • DP(W3) antibody
    • DP(W4) antibody
    • HLA class II histocompatibility antigen DP alpha 1 chain antibody
    • HLA class II histocompatibility antigen DP alpha chain antibody
    • HLA DP1A antibody
    • HLA DPA 1 antibody
    • HLA SB alpha chain antibody
    • HLADP antibody
    • HLADPA1 antibody
    • HLASB antibody
    • HLASB histocompatibility type antibody
    • Human MHC class II HLA SB alpha gene antibody
    • Major histocompatibility complex class II DP alpha 1 antibody
    • MHC class II antigen antibody
    • MHC class II DP3 alpha antibody
    • MHC class II DPA1 antibody
    • MHC class II HLA DPA1 antigen antibody
    • PLT1 antibody
    • Primed lymphocyte test 1 antibody
    see all


  • Raw 246.7 cells stained for HLA-DP (colored green) using ab20897 in ICC/IF. The cells were fixed with 4% formaldehyde (10 min) then permeabilized using 0.1% Triton X-100 in PBS buffer and then incubated in 1% bovine serum albumin (BSA) + 10% normal goat serum + 0.3 M glycine + 0.1% Tween-20 in PBS buffer for 1 hour to further permeabilize the cells and block non-specific protein-protein interactions. The cells were then incubated with the HLA-DP antibody ab20897 at 5 µg/ml overnight at +4°C. The secondary antibody (colored green) was Alexa Fluor® 488 goat anti-mouse (ab150117) IgG (H+L) preadsorbed, used at a 1/1000 dilution for 1 hour. Alexa Fluor® 594 WGA was used to label plasma membranes (colored red) at a 1/200 dilution for 1 hour at room temperature. DAPI was used to stain the cell nuclei (colored blue) at a concentration of 1.43 µM for 1 hour at room temperature.


This product has been referenced in:

  • Zhou J  et al. Immunity to X-linked inhibitor of apoptosis protein (XIAP) in malignant melanoma and check-point blockade. Cancer Immunol Immunother 68:1331-1340 (2019). Read more (PubMed: 31317218) »
  • Deo SS  et al. Stimulation with lysates of Aspergillus terreus, Candida krusei and Rhizopus oryzae maximizes cross-reactivity of anti-fungal T cells. Cytotherapy 18:65-79 (2016). Blocking ; Human . Read more (PubMed: 26552765) »
See all 17 Publications for this product

Customer reviews and Q&As

1-3 of 3 Abreviews or Q&A


Thank you very much for your reply.

The binding affinity and mechanism varies between blocking antibodies, butthey do seem to generally act as antagonists. These kinds of characteristics need to be determined for each individual antibody and antigen. For the HLA antibody Ab23632, we only have one publication demonstrating its use in a blocking experiment and there doesn't seem to be any data regarding the binding affinity of the antibody-


The specific time the antibody will bind to a single antigen depends on factors of the experiment such as temperature, concentration of the antibody in the media, cell type, etc. I wouldn't expect the blocking to be effective for many days, but probably the effect will be noticeable on the hour-scale.

I am sorry that we don't havemore information regarding this, but if you have further questions or need anything else, please let me know and I'll be happy to help.

Read More


Thank you again for contacting us and for your patience while I've been in touch with the lab about your enquiry.

Ab20897 against HLA-DP has not been tested in a blocking experiment at this time, though it is possible that it will work in such an assay. Unfortunately none of our other HLA-DP antibodies seem tohave been tested for blocking ability atthis time. If you're interested in trying Ab20897 in a blocking experiment, we do have a testing discount programand I'd be happy to send more information about this if you're interested.

The clone SPV-L3 against HLA-DQ, which we carry as Ab23632, has been used in a blocking experiment in the following publication-


We would recommend removing the sodium azide from Ab23632 before incubating it with live cells, as azide will cause cell death. An antibody purification kit such as Ab102784 can be used to remove the azide-


I hope that this information is useful, but please let me know if you have any further questions and I'll be happy to help.

Read More


Thank you very much for contacting us with your enquiry.

Theterm "functional studies" can be used to describe several different kinds of assays, and sometimes blocking assays are included in this categorization so there isn't a specific difference between blocking and functional studies antibodies.

For example, ab136320 is listed as being tested in functional studies and a blocking assay, however after checking through our internal notes I see that the functional study was actually a blocking assay. Ab23755 was also tested in a functional study, however this was a tissue typing and crossmatching experiment,not a blocking assay. The details of the functional study are often on the datasheet in the "Application Notes" section, however this is not always the case. I apologize that these designationsare not more straight-forward and clear.

Are you using human samples? Ab136320 will be a good antibody for blocking HLA DR, but we don't currently have any antibodies listed as being tested for blocking of HLA DP and HLA DQ. There are two antibodies to these targets that might work in such an assay, ab20897 (HLA DP) and ab23632 (HLA DQ), but I'm checking with the lab to make sure they've been tested for blocking ability. I'll get back to you as soon as I have confirmed this.

I hope that this information will be useful, but please let me know if you have any further questions and I'll be happy to help.

Read More

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