Support & Resources


CD9 Monoclonal Mouse Antibody (HI9a) – Biotium Choice

CD9 (clone HI9a) is a validated mouse monoclonal antibody that recognizes the human tetraspanin protein CD9. The antibody belongs to the Biotium Choice list of select antibodies that have been validated and optimized in-house for optimal performance.

Product Attributes

Antibody number




Biotium Choice Antibody


Antibody type

Biotium Choice Flow Antibodies, Primary



Host species





IgG1, kappa

Antibody reactivity (target)



Tetraspanin-29 (TSPAN29); BA-2/p24 antigen; BA2; BTCC1; CD9; Cell growth-inhibiting gene 2 protein; DRAP27; GIG2; Leukocyte antigen MIC3; MIC3; Motility-related protein (MRP1); p25

Species reactivity

Baboon, Bovine, Cynomolgus monkey, Dog, Horse, Human, Non-human primates, Rabbit, Sheep

Human gene symbol


Entrez gene ID




Molecular weight

25 kDa

Antibody target cellular localization

Exosomes/EVs, Plasma membrane

Cell/tissue expression

Exosomes, Platelets, Basophils, Eosinophils, Epithelial cells, Lymphocytes

Verified antibody applications

Flow (surface) (verified), WB (verified), IF (verified)

Positive control

Human peripheral blood platelets, BT-20, MCF-7, HeLa, or ZR-75 cells. Cervix or esophagus tissue.

Antibody application notes

Flow Cytometry: 0.5-1 ug/mL (or, 0.05-0.1 ug/million cells), Immunofluorescence: 1 ug/mL, Western Blot: 0.05 ug/mL

Antibody research areas


Antibody/conjugate formulation

Purified: 0.5 mg/mL in PBS/0.05% azide, Conjugates: PBS/0.1% BSA/0.05% azide

Shelf life

Guaranteed for at least 24 months from date of receipt when stored as recommended

Storage Conditions

Store at 2 to 8 °C

Volume per assay

5 uL/test

Regulatory status

For research use only (RUO)

Catalog #
25 tests
100 tests
Clear selection
Send us an inquiry
Please fill in the form below
(This product is available by special order only)

Wishlist updated! View wishlist

Product Description

CD9 (clone HI9a) is a mouse monoclonal antibody that recognizes the human tetraspanin protein CD9. This antibody belongs to the Biotium Choice list of select antibodies that have been validated and optimized in-house for optimal performance. This antibody has been validated in flow cytometry, in immunofluorescence microscopy, and in western blot. The antibody is available conjugated to R-PE or Astral™ tandem dyes. They are supplied in PBS, 0.1% BSA, 0.05% azide.

CD9 is a type IV transmembrane glycoprotein with four transmembrane domains. CD9 on pre-B cells may play a role in cell-cell adhesion. In addition, CD9 may play a role in signal transduction mediated by interaction with low molecular weight GTP binding proteins. CD9 is expressed on early B cells, eosinophils, basophils and activated T cells and is a major component of the platelet cell surface. It is also expressed on most non-T acute lymphoblastic leukemia cells and on some acute myeloid and chronic lymphoid leukemia.

Tetraspanin proteins CD9, CD63, and CD81, are the most common proteins used as exosome markers. Tetraspanins are plasma membrane proteins with many proposed functions, including activation and sorting of other membrane proteins. They are also thought to play a role in the targeting of proteins to multivesicular bodies (MVBs) and exosomes. These tetraspanins are broadly expressed on many cell types and can therefore be detected on many types of exosomes, but their expression levels vary depending on the cell type of origin.

As an isotype control, we recommend Isotype Control, Monoclonal Mouse IgG1 Kappa (IGG1/1331) for this antibody. View our full catalog of Biotium Choice antibodies, optimized and validated for the best results in flow cytometry.

Exosome Stains and Antibodies

Biotium also offers ExoBrite™ CD9 Flow Antibody and ExoBrite™ CD9 Western Antibody that are validated for optimal detection of isolated exosomes by flow cytometry or western blotting. Learn more about our products for exosome research.

CD9 Monoclonal Mouse Antibody (HI9a) - Biotium Choice

ConjugationEx/EmConc.SizeCatalog No.Availability
CF®405M416/452 nm100 ug/mL25 tests (125 uL)P003S-405M-125Discontinued, see replacement P015-405M
100 tests (500 uL)P003S-405M-500
CF®488A490/516 nm100 ug/mL25 tests (125 uL)P003S-488A-125Discontinued, see replacement P015-488A
100 tests (500 uL)P003S-488A-500
CF®568562/584 nm100 ug/mL25 tests (125 uL)P003S-568-125Discontinued, see replacement P015-568
100 tests (500 uL)P003S-568-500
RPE-Astral™616496, 546, 566/617 nm100 ug/mL25 tests (125 uL)P003S-R616-125Available
100 tests (500 uL)P003S-R616-500
CF®647Plus652/668 nm100 ug/mL25 tests (125 uL)P003S-647P-125Discontinued, see replacement P015-647P
100 tests (500 uL)P003S-647P-500
CF®700696/721 nm100 ug/mL25 tests (125 uL)P003S-700-125Discontinued, see replacement P015-700
100 tests (500 uL)P003S-700-500
APC-Astral™813633, 638/813 nm100 ug/mL25 tests (125 uL)P003S-A813-125Available
100 tests (500 uL)P003S-A813-500
R-PE496, 546, 565/576 nm50 ug/mL25 tests (125 uL)P003S-RPE-125Available
100 tests (500 uL)P003S-RPE-500
Purified (BSA-free)N/A0.5 mg/mL200 uL (100 ug)P003-200uLDiscontinued, see replacement P015

You may also like…