Anti-CD21 antibody [SP186] - Carrier free (ab240987)

Anti-CD21 [SP186] antibody (ab240987) is a rabbit monoclonal antibody that is provided in a PBS only formulation free from BSA and azide. Formulated to be conjugation-ready. It is used to detect CD21 in Western Blot, Flow Cytometry (Intra), Flow Cytometry, IHC-P, IHC-Fr. Suitable for Human, Mouse, Rat samples.

- BSA,?sodium azide, and glycerol-free?for consistent conjugation with fluorochromes, enzymes and more

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Images

Flow Cytometry (Intracellular) - Anti-CD21 antibody [SP186] - BSA and Azide free (AB240987), expandable thumbnail

Publications

Key facts

Isotype: IgG
Host species: Rabbit
Storage buffer: pH: 7.2 - 7.4
Constituents: PBS
Form: Liquid
Clonality: Monoclonal

Immunogen

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

Reactivity data

Select an application

Product promiseTestedExpectedPredictedNot recommended

	IHC-P	Flow Cyt (Intra)	WB	IHC-Fr
Human	Tested	Tested	Tested	Expected
Mouse	Expected	Expected	Not recommended	Tested
Rat	Tested	Tested	Expected	Expected

Tested
Tested

Species	Dilution info	Notes
Species Rat	Dilution info -	Notes Perform heat-mediated antigen retrieval with citrate buffer pH 6 before commencing with IHC staining protocol.
Species Human	Dilution info -	Notes Perform heat-mediated antigen retrieval with citrate buffer pH 6 before commencing with IHC staining protocol.

Expected
Expected

Species	Dilution info	Notes
Species Mouse	Dilution info -	Notes Perform heat-mediated antigen retrieval with citrate buffer pH 6 before commencing with IHC staining protocol.

Tested
Tested

Species	Dilution info	Notes
Species Rat, Human	Dilution info -	Notes -

Expected
Expected

Species	Dilution info	Notes
Species Mouse	Dilution info Use at an assay dependent concentration.	Notes -

Tested
Tested

Species	Dilution info	Notes
Species Human	Dilution info -	Notes -

Expected
Expected

Species	Dilution info	Notes
Species Rat	Dilution info Use at an assay dependent concentration.	Notes -

Not recommended
Not recommended

Species	Dilution info	Notes
Species Mouse	Dilution info -	Notes -

Tested
Tested

Species	Dilution info	Notes
Species Mouse	Dilution info -	Notes -

Expected
Expected

Species	Dilution info	Notes
Species Rat, Human	Dilution info Use at an assay dependent concentration.	Notes -

Associated Products

Select an associated product type

15 products for Alternative Product

5 products for Alternative Version

Target data

See full target information CR2

Function

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). Induces also 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.

Alternative names

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

Key facts

Isotype: IgG
Host species: Rabbit
Storage buffer: pH: 7.2 - 7.4
Constituents: PBS
Form: Liquid
Clonality: Monoclonal
Immunogen: The exact immunogen used to generate this antibody is proprietary information.
Carrier free: Yes
Clone number: SP186
Purification technique: Affinity purification Protein A/G
Concentration
Purification notes: Purified from TCS by protein A/G.

Storage

Shipped at conditions: Blue Ice
Appropriate short-term storage conditions: +4°C
Appropriate long-term storage conditions: +4°C
Storage information: Do Not Freeze

Notes

ab240987 is the carrier-free version of Anti-CD21 antibody [SP186] - C-terminal ab227662.

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.

Conjugation ready
Our carrier-free antibodies are typically supplied in a PBS-only formulation, purified and free of BSA, sodium azide and glycerol. This conjugation-ready format is designed for use with fluorochromes, metal isotopes, oligonucleotides, and enzymes, which makes them ideal for antibody labelling, functional and cell-based assays, flow-based assays (e.g. mass cytometry) and Multiplex Imaging applications.

Use our conjugation kits for antibody conjugates that are ready-to-use in as little as 20 minutes with 1 minute hands-on-time and 100% antibody recovery: available for fluorescent dyes, HRP, biotin and gold.

Compatibility
This product is compatible with the Maxpar^® Antibody Labeling Kit from Fluidigm, without the need for antibody preparation. Maxpar^® is a trademark of Fluidigm Canada Inc.

Supplementary info

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

Activity summary

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.

Associated diseases and disorders

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.

Product promise

We are dedicated to supporting your work with high quality reagents and we are here for you every step of the way should you need us.

In the unlikely event of one of our products not working as expected, you are covered by our product promise.

Full details and terms and conditions can be found here:
Terms & Conditions.

15 product images

Flow Cytometry (Intracellular) - Anti-CD21 antibody [SP186] - BSA and Azide free (ab240987)
Flow Cytometry analysis of Raji (human Burkitt's lymphoma B lymphocyte) cells labeling CD21 with purified Anti-CD21 antibody [SP186] - C-terminal ab227662 at 1:20 dilution (5.3 µg/ml) - Red. Cells were fixed with 4% paraformaldehyde . A Goat anti rabbit IgG (Alexa Fluor® 488, Goat Anti-Rabbit IgG H&L (Alexa Fluor® 488) preadsorbed ab150081) secondary antibody was used at 1:2000 dilution. Isotype control - Rabbit monoclonal IgG (Rabbit IgG, monoclonal [EPR25A] - Isotype Control ab172730) - Black. Unlabeled control - Blue.This data was developed using the same antibody clone in a different buffer formulation containing PBS, BSA, glycerol, and sodium azide (ab240987)
Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) - Anti-CD21 antibody [SP186] - BSA and Azide free (ab240987)
This data was developed using Anti-CD21 antibody [SP186] - C-terminal ab227662, the same antibody clone in a different buffer formμlation.
Immunohistochemical analysis of paraffin-embedded Mouse cardiac muscle tissue labeling CD21 with Anti-CD21 antibody [SP186] - C-terminal ab227662 at 1/100 (0.28 μg/ml) dilution followed by a ready to use LeicaDS9800 (Bond™ Polymer Refine Detection). Negative control: no staining on mouse cardiac muscle. The section was incubated with Anti-CD21 antibody [SP186] - C-terminal ab227662 for 30 mins at room temperature.The immunostaining was performed on a Leica Biosystems BOND® RX instrument Counterstained with Hematoxylin.
Secondary antibody only control: Secondary antibody is a ready to use LeicaDS9800 (Bond™ Polymer Refine Detection).
Heat mediated antigen retrieval with Tris-EDTA buffer (pH 9.0, epitope retrieval solution) for 20 mins
Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) - Anti-CD21 antibody [SP186] - BSA and Azide free (ab240987)
This data was developed using Anti-CD21 antibody [SP186] - C-terminal ab227662, the same antibody clone in a different buffer formμlation.
Immunohistochemical analysis of paraffin-embedded Mouse liver tissue labeling CD21 with Anti-CD21 antibody [SP186] - C-terminal ab227662 at 1/100 (0.28 μg/mL) dilution followed by a ready to use LeicaDS9800 (Bond™ Polymer Refine Detection). Negative control: no staining on mouse liver. The section was incubated with Anti-CD21 antibody [SP186] - C-terminal ab227662 for 30 mins at room temperature.The immunostaining was performed on a Leica Biosystems BOND® RX instrument Counterstained with Hematoxylin.
Secondary antibody only control: Secondary antibody is a ready to use LeicaDS9800 (Bond™ Polymer Refine Detection).
Heat mediated antigen retrieval with Tris-EDTA buffer (pH 9.0, epitope retrieval solution) for 20 mins
Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) - Anti-CD21 antibody [SP186] - BSA and Azide free (ab240987)
This data was developed using Anti-CD21 antibody [SP186] - C-terminal ab227662, the same antibody clone in a different buffer formμlation.
Immunohistochemical analysis of paraffin-embedded Rat spleen tissue labeling CD21 with Anti-CD21 antibody [SP186] - C-terminal ab227662 at 1/100 (0.28 μg/ml) dilution followed by a ready to use LeicaDS9800 (Bond™ Polymer Refine Detection). Positive staining on rat spleen. The section was incubated with Anti-CD21 antibody [SP186] - C-terminal ab227662 for 30 mins at room temperature.The immunostaining was performed on a Leica Biosystems BOND® RX instrument Counterstained with Hematoxylin.
Secondary antibody only control: Secondary antibody is a ready to use LeicaDS9800 (Bond™ Polymer Refine Detection).
Heat mediated antigen retrieval with Tris-EDTA buffer (pH 9.0, epitope retrieval solution) for 20 mins
Flow Cytometry (Intracellular) - Anti-CD21 antibody [SP186] - BSA and Azide free (ab240987)
Flow cytometric analysis of Raji (human Burkitt's lymphoma cell line) cell line labeling CD21 with Anti-CD21 antibody [SP186] - C-terminal ab227662 at 1/100 dilution (green) compared with a Rabbit IgG negative control (blue).
This data was developed using the same antibody clone in a different buffer formulation containing PBS, BSA, and sodium azide (Anti-CD21 antibody [SP186] - C-terminal ab227662).
Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) - Anti-CD21 antibody [SP186] - BSA and Azide free (ab240987)
Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) analysis of Human tonsil tissue sections labeling CD21 with Anti-CD21 antibody [SP186] - C-terminal ab227662 at 1/100 dilution (1.06 μg/ml). Heat mediated antigen retrieval with Citrate buffer (pH 6.0, epitope retrieval solution 1) for 10mins. Goat Anti-Rabbit & Mouse IgG (HRP) was used as the secondary antibody. Hematoxylin was used as a counterstain. Positive staining on the human tonsil, performed on a Leica Biosystems BOND™RX instrument.
The section was incubated with Anti-CD21 antibody [SP186] - C-terminal ab227662 for 10 mins at room temperature.
This image was generated using Anti-CD21 antibody [SP186] - C-terminal ab227662, the same clone, but with a different buffer formulation.
Flow Cytometry (Intracellular) - Anti-CD21 antibody [SP186] - BSA and Azide free (ab240987)
Flow Cytometry analysis of 2.4G2 (rat B cell lymphoma B lymphocyte) cells labeling CD21 with purified Anti-CD21 antibody [SP186] - C-terminal ab227662 at 1:200 dilution (0.53 µg/ml) - Red. Cells were fixed with 4% paraformaldehyde . A Goat anti rabbit IgG (Alexa Fluor® 488, Goat Anti-Rabbit IgG H&L (Alexa Fluor® 488) preadsorbed ab150081) secondary antibody was used at 1:2000 dilution. Isotype control - Rabbit monoclonal IgG (Rabbit IgG, monoclonal [EPR25A] - Isotype Control ab172730) - Black. Unlabeled control - Blue.This data was developed using the same antibody clone in a different buffer formulation containing PBS, BSA, glycerol, and sodium azide (ab240987)
Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) - Anti-CD21 antibody [SP186] - BSA and Azide free (ab240987)
This data was developed using Anti-CD21 antibody [SP186] - C-terminal ab227662, the same antibody clone in a different buffer formμlation.
Immunohistochemical analysis of paraffin-embedded Mouse spleen tissue labeling CD21 with Anti-CD21 antibody [SP186] - C-terminal ab227662 at 1/100 (0.28 μg/ml) dilution followed by a ready to use LeicaDS9800 (Bond™ Polymer Refine Detection). Positive staining on mouse spleen. The section was incubated with Anti-CD21 antibody [SP186] - C-terminal ab227662 for 30 mins at room temperature.The immunostaining was performed on a Leica Biosystems BOND® RX instrument Counterstained with Hematoxylin.
Secondary antibody only control: Secondary antibody is a ready to use LeicaDS9800 (Bond™ Polymer Refine Detection).
Heat mediated antigen retrieval with Tris-EDTA buffer (pH 9.0, epitope retrieval solution) for 20 mins
Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) - Anti-CD21 antibody [SP186] - BSA and Azide free (ab240987)
Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) analysis of Rat spleen tissue sections labeling CD21 with Anti-CD21 antibody [SP186] - C-terminal ab227662 at 1/100 dilution (1.06 μg/ml). Heat mediated antigen retrieval with Citrate buffer (pH 6.0, epitope retrieval solution 1) for 10mins. Goat Anti-Rabbit & Mouse IgG (HRP) was used as the secondary antibody. Hematoxylin was used as a counterstain. Positive staining on the rat spleen, performed on a Leica Biosystems BOND™ RX instrument.
The section was incubated with Anti-CD21 antibody [SP186] - C-terminal ab227662 for 10 mins at room temperature.
This image was generated using Anti-CD21 antibody [SP186] - C-terminal ab227662, the same clone, but with a different buffer formulation.
Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) - Anti-CD21 antibody [SP186] - BSA and Azide free (ab240987)
Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) analysis of Human spleen tissue sections labeling CD21 with Anti-CD21 antibody [SP186] - C-terminal ab227662 at 1/100 dilution (1.06 μg/ml). Heat mediated antigen retrieval with Citrate buffer (pH 6.0, epitope retrieval solution 1) for 10mins. Goat Anti-Rabbit & Mouse IgG (HRP) was used as the secondary antibody. Hematoxylin was used as a counterstain. Positive staining on the human spleen, performed on a Leica Biosystems BOND™ RX instrument.
The section was incubated with Anti-CD21 antibody [SP186] - C-terminal ab227662 for 10 mins at room temperature.
This image was generated using Anti-CD21 antibody [SP186] - C-terminal ab227662, the same clone, but with a different buffer formulation.
Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) - Anti-CD21 antibody [SP186] - BSA and Azide free (ab240987)
Formalin-fixed, paraffin-embedded human tonsil tissue stained for CD21 using Anti-CD21 antibody [SP186] - C-terminal ab227662 at 1/100 dilution in immunohistochemical analysis.
This data was developed using the same antibody clone in a different buffer formulation containing PBS, BSA, and sodium azide (Anti-CD21 antibody [SP186] - C-terminal ab227662).
Immunohistochemistry (Frozen sections) - Anti-CD21 antibody [SP186] - BSA and Azide free (ab240987)
This data was developed using Anti-CD21 antibody [SP186] - C-terminal ab227662, the same antibody clone in a different buffer formμlation.
Immunohistochemical analysis of 4% PFA-fixed, 0.2% Triton X-100 permeabilized frozen mouse spleen tissue labeling CD21 with Anti-CD21 antibody [SP186] - C-terminal ab227662 at 1/100 (0.28 μg/ml) dilution followed by Goat Anti-Rabbit IgG H&L (Alexa Fluor® 488) ab150077 Goat Anti-Rabbit IgG H&L (Alexa Fluor® 488) at 1/1000 2 μg/ml dilution (Green). membranous staining on mouse spleen is observed. The nuclear counterstain was DAPI (Blue).
Secondary antibody control: Secondary antibody is Goat Anti-Rabbit IgG H&L (Alexa Fluor® 488) ab150077 Goat Anti-Rabbit IgG H&L (Alexa Fluor® 488) at 1000 2 μg/ml dilution.
Heat mediated antigen retrieval using sodium citrate buffer (10mM citrate pH 6.0 + 0.05% Tween-20).
Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) - Anti-CD21 antibody [SP186] - BSA and Azide free (ab240987)
Formalin-fixed, paraffin-embedded human reactive lymph node tissue stained for CD21 using Anti-CD21 antibody [SP186] - C-terminal ab227662 at 1/100 dilution in immunohistochemical analysis.
This data was developed using the same antibody clone in a different buffer formulation containing PBS, BSA, and sodium azide (Anti-CD21 antibody [SP186] - C-terminal ab227662).
Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) - Anti-CD21 antibody [SP186] - BSA and Azide free (ab240987)
Formalin-fixed, paraffin-embedded human spleen tissue stained for CD21 using Anti-CD21 antibody [SP186] - C-terminal ab227662 at 1/100 dilution in immunohistochemical analysis.
This data was developed using the same antibody clone in a different buffer formulation containing PBS, BSA, and sodium azide (Anti-CD21 antibody [SP186] - C-terminal ab227662).
Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) - Anti-CD21 antibody [SP186] - BSA and Azide free (ab240987)
Formalin-fixed, paraffin-embedded human colon tissue stained for CD21 using Anti-CD21 antibody [SP186] - C-terminal ab227662 at 1/100 dilution in immunohistochemical analysis.
This data was developed using the same antibody clone in a different buffer formulation containing PBS, BSA, and sodium azide (Anti-CD21 antibody [SP186] - C-terminal ab227662).