CD81 Monoclonal antibody

CD81 Monoclonal Antibody for FC, IF, IHC, WB,ELISA

Host / Isotype

Mouse / IgG1


Human and More (4)







Cat no : 66866-1-Ig


CD81, CD81 antigen, CD81 molecule, S5.7, TAPA1, Tetraspanin 28, Tspan 28, TSPAN28

Tested Applications

Positive WB detected inRaji cells, Jurkat cells, LPS treated THP-1 cells, Ramos cells, Daudi cells
Positive IHC detected inhuman tonsillitis tissue
Note: suggested antigen retrieval with TE buffer pH 9.0; (*) Alternatively, antigen retrieval may be performed with citrate buffer pH 6.0
Positive IF detected inhuman tonsillitis tissue
Positive FC detected inJurkat cells, Raji cells
Planning an IF experiment? We recommend our CoraLite®488 conjugated versions of this antibody.

Recommended dilution

Western Blot (WB)WB : 1:1000-1:6000
Immunohistochemistry (IHC)IHC : 1:500-1:2000
Immunofluorescence (IF)IF : 1:600-1:2400
Sample-dependent, check data in validation data gallery

Product Information

66866-1-Ig targets CD81 in WB, IHC, IF, FC applications and shows reactivity with Human samples.

Tested Reactivity Human
Cited Reactivity human, mouse, pig, rat
Host / Isotype Mouse / IgG1
Class Monoclonal
Type Antibody
Immunogen CD81 fusion protein Ag27298
Full Name CD81 molecule
Calculated molecular weight 26 kDa
Observed molecular weight 22 kDa
GenBank accession numberBC002978
Gene symbol CD81
Gene ID (NCBI) 975
Conjugate Unconjugated
Form Liquid
Purification Method Protein G purification
Storage Buffer PBS with 0.02% sodium azide and 50% glycerol pH 7.3.
Storage ConditionsStore at -20°C. Stable for one year after shipment. Aliquoting is unnecessary for -20oC storage.

Background Information

CD81 (also known as TAPA1 or TSPAN28) is a membrane protein of the tetraspanin superfamily, which are characterized by the presence of four conserved transmembrane regions. Many of these members are expressed on leukocytes and have been implicated in signal transduction, cell-cell interactions, and cellular activation and development. CD81 is involved in signal transduction and cell adhesion in the immune system (PMID: 9597125). CD81 has also been identified as en essential receptor for HCV (hepatitis C virus) (PMID: 21428934).


Product Specific Protocols
WB protocol for CD81 antibody 66866-1-IgDownload protocol
IHC protocol for CD81 antibody 66866-1-IgDownload protocol
IF protocol for CD81 antibody 66866-1-IgDownload protocol
FC protocol for CD81 antibody 66866-1-IgDownload protocol
Standard Protocols
Click here to view our Standard Protocols



J Biol Chem

Modulation of calreticulin expression reveals a novel exosome mediated mechanism of Z variant alpha-1 antitrypsin disposal.

Authors - Nazli Khodayari

J Exp Clin Cancer Res

Exosomal circRNA-100338 promotes hepatocellular carcinoma metastasis via enhancing invasiveness and angiogenesis.

Authors - Xiu-Yan Huang

Front Cell Dev Biol

Down-Regulated Exosomal MicroRNA-221 - 3p Derived From Senescent Mesenchymal Stem Cells Impairs Heart Repair.

Authors - Ling Sun

J Extracell Vesicles

Hepatitis A virus structural protein pX interacts with ALIX and promotes the secretion of virions and foreign proteins through exosome-like vesicles.

Authors - Wang Jiang

Clin Transl Med

HucMSC-exosomes carrying miR-326 inhibit neddylation to relieve inflammatory bowel disease in mice.

Authors - Gaoying Wang

Int J Mol Sci

Development of Novel High-Resolution Size-Guided Turbidimetry-Enabled Particle Purification Liquid Chromatography (PPLC): Extracellular Vesicles and Membraneless Condensates in Focus.

Authors - Hussein Kaddour


The reviews below have been submitted by verified Proteintech customers who received an incentive forproviding their feedback.


Xiaogang (Verified Customer) (10-21-2021)

I recently bought this CD81 antibody to detect CD81 from EVs purified from human and mouse cell lines. The antibody works well to detect CD81 by immunoblot.

  • Applications: Western Blot
  • Primary Antibody Dilution: 1:1000
  • Cell Tissue Type: RAW264.7 and differentiated THP-1 cells
CD81 Antibody Western Blot validation (1:1000 dilution) in RAW264.7 and differentiated THP-1 cells (Cat no:66866-1-Ig)