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AB75985

Anti-CD21 antibody [EP3093]

4

(6 Reviews)

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(53 Publications)

Anti-CD21 antibody [EP3093] (ab75985) is a rabbit monoclonal antibody detecting CD21 in Western Blot, IP, IHC-P, ICC/IF. Suitable for Human.

- Biophysical QC for unrivalled batch-batch consistency
- Over 30 publications
- Trusted since 2009

View Alternative Names

CD21, C3DR, CR2, Complement receptor type 2, Cr2, Complement C3d receptor, Epstein-Barr virus receptor, EBV receptor

4 Images
Immunocytochemistry/ Immunofluorescence - Anti-CD21 antibody [EP3093] (AB75985)
  • ICC/IF

Lab

Immunocytochemistry/ Immunofluorescence - Anti-CD21 antibody [EP3093] (AB75985)

Immunocytochemistry analysis of Raji (Human Burkitt's lymphoma B lymphocyte) cells labeling CD21 with Purified ab75985 at 1 : 50 dilution (10 μg/ml). Cells were fixed in 4% Paraformaldehyde and permeabilized with 0.1% tritonX-100. Cells were counterstained with ab195889 Anti-alpha Tubulin antibody [DM1A]+H21 : L21 - Microtubule Marker (Alexa Fluor® 594) 1 : 200 (2.5 μg/ml). Goat anti rabbit IgG (Alexa Fluor® 488, ab150077) was used as the secondary antibody at 1 : 1000 (2 μg/ml) dilution. DAPI (blue) was used as nuclear counterstain. PBS instead of the primary antibody was used as the secondary antibody only control.

Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) - Anti-CD21 antibody [EP3093] (AB75985)
  • IHC-P

Lab

Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) - Anti-CD21 antibody [EP3093] (AB75985)

Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) analysis of human tonsil tissue sections labeling CD21 with Purified ab75985 at 1 : 8000 dilution (0.066 μg/ml). Heat mediated antigen retrieval was performed using Heat mediated antigen retrieval using Bond™ Epitope Retrieval Solution 1 (pH 6.0) . Tissue was counterstained with Hematoxylin. Rabbit specific IHC polymer detection kit HRP/DAB (ab209101) secondary antibody was used at 1 : 0 dilution. PBS instead of the primary antibody was used as the negative control.

Immunoprecipitation - Anti-CD21 antibody [EP3093] (AB75985)
  • IP

Unknown

Immunoprecipitation - Anti-CD21 antibody [EP3093] (AB75985)

Purified ab75985 at 1/100 dilution (2μg) immunoprecipitating CD21 in Daudi whole cell lysate.
Lane 1 (input) : Daudi (Human Burkitt's lymphoma lymphoblast) whole cell lysate 10μg
Lane 2 (+) : ab75985 + Daudi whole cell lysate.
Lane 3 (-) : Rabbit monoclonal IgG (ab172730) instead of ab75985 in Daudi whole cell lysate.
VeriBlot for IP Detection Reagent (HRP) (ab131366) (1/1000 dilution) was used for Western blotting.
Blocking Buffer and concentration : 5% NFDM/TBST.
Diluting buffer and concentration : 5% NFDM/TBST.
Observed band size : 155 kDa
The band at around 15kDa could be cleavage form. (PMID : 9647256)

All lanes:

Immunoprecipitation - Anti-CD21 antibody [EP3093] (ab75985)

Predicted band size: 113 kDa

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Western blot - Anti-CD21 antibody [EP3093] (AB75985)
  • WB

Unknown

Western blot - Anti-CD21 antibody [EP3093] (AB75985)

All lanes:

Western blot - Anti-CD21 antibody [EP3093] (ab75985) at 1/20000 dilution

Lane 1:

Daudi (Human Burkitt's lymphoma lymphoblast) whole cell lysate at 20 µg

Lane 2:

Raji (Human Burkitt's lymphoma B lymphocyte) whole cell lysate at 20 µg

Secondary

All lanes:

Western blot - Goat Anti-Rabbit IgG H&L (HRP) (<a href='/en-us/products/secondary-antibodies/goat-rabbit-igg-h-l-hrp-ab97051'>ab97051</a>) at 1/20000 dilution

Predicted band size: 113 kDa

false

Key facts

Host species

Rabbit

Clonality

Monoclonal

Clone number

EP3093

Isotype

IgG

Carrier free

No

Reacts with

Human

Applications

IP, ICC/IF, IHC-P, WB

applications

Immunogen

The exact immunogen used to generate this antibody is proprietary information.

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Reactivity data

{ "title": "Reactivity Data", "filters": { "stats": ["", "Species", "Dilution Info", "Notes"], "tabs": { "all-applications": {"fullname" : "All Applications", "shortname": "All Applications"}, "IHCP" : {"fullname" : "Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections)", "shortname":"IHC-P"}, "IP" : {"fullname" : "Immunoprecipitation", "shortname":"IP"}, "WB" : {"fullname" : "Western blot", "shortname":"WB"}, "ICCIF" : {"fullname" : "Immunocytochemistry/ Immunofluorescence", "shortname":"ICC/IF"} }, "product-promise": { "all": "all", "testedAndGuaranteed": "tested", "guaranteed": "expected", "predicted": "predicted", "notRecommended": "not-recommended" } }, "values": { "Human": { "IHCP-species-checked": "testedAndGuaranteed", "IHCP-species-dilution-info": "1/8000", "IHCP-species-notes": "<p>For unpurified use at dilution 1/250 to 1/500</p> Perform heat-mediated antigen retrieval before commencing with IHC staining protocol.", "IP-species-checked": "testedAndGuaranteed", "IP-species-dilution-info": "1/100", "IP-species-notes": "<p></p>", "WB-species-checked": "testedAndGuaranteed", "WB-species-dilution-info": "1/2000 - 1/5000", "WB-species-notes": "<p></p>", "ICCIF-species-checked": "testedAndGuaranteed", "ICCIF-species-dilution-info": "1/50", "ICCIF-species-notes": "<p>For unpurified use at dilution 1/250 to 1/500</p>" } } }
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Product details

What is this antibody validated in?
Anti-CD21 antibody [EP3093] (ab75985) is a rabbit recombinant monoclonal antibody and is validated for use in Western Blot (WB), Immunoprecipitation (IP), Immunohistochemistry (IHC-P), Immunocytochemistry/immunofluorescence (ICC/IF) in Human samples.

What is the molecular weight of CD21?
Anti-CD21 [EP3093] (ab75985) specifically detects a band for CD21 (UniProt: P20023) at a molecular weight of 113kDa.

Trusted by the scientific community
Anti-CD21 [EP3093] (ab75985) was first used in a scientific publication in 2009 and has been cited over 30 times in peer-reviewed journals.

Reviewed by scientists
Anti-CD21 [EP3093] (ab75985) has over 5 independent reviews from customers.

Trial sizes available!
Test your antibody or perform pre-screening before committing to a larger quantity. Sold in 10µl. Discover our selection of trial-size antibodies.

Other related products
We have a range of other formats of antibody clone [EP3093] also available for your convenience: ab75985, Carrier free - ab193554, HRP - ab202354, Alexa Fluor® 488 - ab202692, Alexa Fluor® 647 - ab202693, Carrier free - ab271855, Alexa Fluor® 594 - ab281930, Alexa Fluor® 555 - ab282007, Biotin - ab322303, Alexa Fluor® 555 - ab322950

Patented technology
Our RabMAb® technology is a patented hybridoma-based technology for making rabbit monoclonal antibodies. For details on our patents, please refer to RabMAb® patents.

What are the advantages of a recombinant monoclonal antibody?
This product is a recombinant monoclonal antibody, which offers several advantages including:

  • - High batch-to-batch consistency and reproducibility
  • - Improved sensitivity and specificity
  • - Long-term security of supply
  • - Animal-free batch production

For more information, read more on recombinant antibodies.

Species reactivity
Rat: We have preliminary internal testing data to indicate this antibody may not react with this species.
Please contact us for more information.

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Properties and storage information

Form
Liquid
Purification technique
Affinity purification Protein A
Storage buffer
pH: 7.2 - 7.4 Preservative: 0.05% Sodium azide Constituents: 50% Tissue culture supernatant, 40% Glycerol (glycerin, glycerine), 9.85% Tris glycine, 0.1% BSA
Shipped at conditions
Blue Ice
Appropriate short-term storage duration
1-2 weeks
Appropriate short-term storage conditions
+4°C
Appropriate long-term storage conditions
-20°C
Aliquoting information
Upon delivery aliquot
Storage information
Avoid freeze / thaw cycle
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Supplementary information

This supplementary information is collated from multiple sources and compiled automatically.

CD21 also known as complement receptor type 2 (CR2) or BU32 is a protein primarily expressed on the surface of B cells and some T cells. It functions as a receptor for complement component C3d EBV (Epstein-Barr Virus) and IFN-α. CD21 weighs approximately 145 kDa and belongs to the membrane protein family. Detection of CD21 can be done via immunohistochemistry (IHC) and blood tests. This marker is valuable for identifying cell populations that have roles in immune responses.
Biological function summary

Complement receptor type 2 is key in the immune system by facilitating B cell activation and proliferation. CD21 forms complexes with CD19 and CD81 increasing the sensitivity of B cells to antigens. This interaction enhances signal transduction enabling B lymphocytes to respond effectively to pathogens. The protein also plays a role in regulating immune tolerance and maintaining humoral immunity being important not only in immune defense but also in preventing autoimmunity.

Pathways

CD21 interacts with complement activation and immune response pathways. It connects with CD19 in a pivotal role where it further amplifies signaling in B lymphocytes. This interaction strengthens the downstream signaling of BCR (B cell receptor) important for antibody production. CD21 contributes to bridging the innate and adaptive immunological pathways by engaging components like C3d.

CD21 shows significant relevance in systemic lupus erythematosus (SLE) and some B cell lymphomas. Deficiencies or mutations in CD21 can lead to defective immune responses and increased susceptibility to autoimmune conditions such as SLE where CD19 is also implicated. Furthermore in Epstein-Barr Virus infections CD21 serves as an entry receptor facilitating pathogen establishment which can result in chronic conditions or even malignancies.
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Product protocols

For this product, it's our understanding that no specific protocols are required. You can visit:
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Target data

Serves as a receptor for various ligands including complement component CD3d, HNRNPU OR IFNA1 (PubMed : 1849076, PubMed : 21527715, PubMed : 7753047). When C3d is bound to antigens, attaches to C3d on B-cell surface and thereby facilitates the recognition and uptake of antigens by B-cells (PubMed : 21527715). This interaction enhances B-cell activation and subsequent immune responses. Forms a complex with several partners on the surface of B-cells including CD19, FCRL5 and CD81, to form the B-cell coreceptor complex that plays a crucial role in B-cell activation and signaling (PubMed : 1383329, PubMed : 30107486). Also induces specific intracellular signaling separately from the BCR and CD19 by activating the tyrosine kinase SRC, which then phosphorylates nucleolin/NCL and triggers AKT and GSK3 kinase activities in a SYK/CD19-independent manner (PubMed : 12938232). Acts as a ligand for CD23 (FcepsilonRII), a low-affinity receptor for IgE, which is expressed on B-cells and other immune cells, and thus participates in the regulation of IgE production (PubMed : 1386409).. (Microbial infection) Acts as a receptor for Epstein-Barr virus.
See full target information CR2
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Publications (53)

Recent publications for all applications. Explore the full list and refine your search

Nature communications 16:6960 PubMed40730843

2025

Single urinary extracellular vesicle proteomics identifies complement receptor CD35 as a biomarker for sepsis-associated acute kidney injury.

Applications

Unspecified application

Species

Unspecified reactive species

Ning Li,Tao-Tao Tang,Menglei Gu,Yu-Qi Fu,Wei-Wei Qian,Nan Nan Ma,An-Ran Shen,Tingting Zhu,Run-Bo Huo,Tao Zhang,Jian-Feng Xie,Lu Zhang,Bi-Cheng Liu,Lin-Li Lv

Cancers 17: PubMed40723259

2025

The Prognostic Role of Tertiary Lymphoid Structures and Immune Microenvironment Signatures in Early-Stage -Mutant Lung Adenocarcinoma.

Applications

Unspecified application

Species

Unspecified reactive species

Wei-Hsun Hsu,Chia-Chi Hsu,Min-Shu Hsieh,James Chih-Hsin Yang

Cell death discovery 11:320 PubMed40651955

2025

Inhibition of VEGFR-3 by SAR131675 decreases renal inflammation and lymphangiogenesis in the murine lupus nephritis model.

Applications

Unspecified application

Species

Unspecified reactive species

Tian Wang,Wenjia Li,Ji-Hyun Yeom,Zhiheng Liu,Kyoung Min Kim,Kyung Pyo Kang

Cells 14: PubMed40498004

2025

Prognostic Significance of Macrophage Phenotypes in Peri-Tumoral Normal Tissue of Early-Stage Breast Cancer.

Applications

Unspecified application

Species

Unspecified reactive species

Marcel Hirschmann,Sören Schnellhardt,Matthias Rübner,Sarah Segelhorst,Oliver Ott,Ramona Erber,Christoph Daniel,Maike Büttner-Herold,Paul Gass,Rainer Fietkau,Luitpold Distel

World journal of surgical oncology 23:131 PubMed40205382

2025

Correlation analysis of tertiary lymphoid structure parameters with the prognosis of patients with locally advanced rectal cancer after neoadjuvant chemotherapy: a retrospective study.

Applications

Unspecified application

Species

Unspecified reactive species

Yingjian Jiang,Chuang Zhang,Yifei Hou,Bin Zhao,Binbin Cui

The Journal of clinical investigation 135: PubMed40166933

2025

ACAT1 regulates tertiary lymphoid structures and correlates with immunotherapy response in non-small cell lung cancer.

Applications

Unspecified application

Species

Unspecified reactive species

Mengxia Jiao,Yifan Guo,Hongyu Zhang,Haoyu Wen,Peng Chen,Zhiqiang Wang,Baichao Yu,Kameina Zhuma,Yuchen Zhang,Jingbo Qie,Yun Xing,Pengyuan Zhao,Zihe Pan,Luman Wang,Dan Zhang,Fei Li,Yijiu Ren,Chang Chen,Yiwei Chu,Jie Gu,Ronghua Liu

PloS one 20:e0311193 PubMed40014629

2025

Aligning cellular and molecular components in age-dependent tertiary lymphoid tissues of kidney and liver.

Applications

Unspecified application

Species

Unspecified reactive species

Naoya Toriu,Yuki Sato,Hiroteru Kamimura,Takahisa Yoshikawa,Masaou Tanaka,Shinya Yamamoto,Shingo Fukuma,Masakazu Hattori,Shuji Terai,Motoko Yanagita

Frontiers in oncology 15:1480461 PubMed39926286

2025

Mature tertiary lymphoid structure associated CD103+ CD8+ Trm cells determined improved anti-tumor immune in breast cancer.

Applications

Unspecified application

Species

Unspecified reactive species

Qin Fang,Shuru Chen,Xiaoyue Chen,Wei Zou,Di Chen,Yukang Huang,Chucheng Wu

Cancers 16: PubMed39594720

2024

Tumor-Infiltrating B Cells and Tissue-Resident Memory T Cells as Prognostic Indicators in Brain Metastases Derived from Gastrointestinal Cancers.

Applications

Unspecified application

Species

Unspecified reactive species

Masasuke Ohno,Shunichiro Kuramitsu,Kimihiro Yamashita,Toru Nagasaka,Shoichi Haimoto,Mitsugu Fujita

Experimental dermatology 33:e15062 PubMed38532566

2024

Analyses of tertiary lymphoid structures observed in cases of Merkel cell carcinoma showing spontaneous regression.

Applications

Unspecified application

Species

Unspecified reactive species

Motoki Nakamura,Maki Yoshimitsu,Tetsuya Magara,Shinji Kano,Hiroshi Kato,Akimichi Morita
View all publications
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Product promise

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