ExoBrite™ CD81 Western Antibody

ExoBrite™ CD81 Western Antibody

ExoBrite™ CD81 Western Antibody provides bright, low-background detection of EV marker CD81 in western blots, available in fluorescent and HRP formats.

ExoBrite™ CD81 Western Antibody cover image

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Validated Antibody for EV Marker CD81 Detection by Fluorescent or Chemiluminescent Western Blot

ExoBrite™ CD81 Western Antibody is a mouse monoclonal IgG1, kappa antibody validated for the detection of CD81 in extracellular vesicle (EV) extracts by western blot. Available in near-infrared fluorescent formats (680/700 and 770/800) and an HRP-conjugated chemiluminescent format, it enables bright, low-background detection of CD81 for exosome and EV protein analysis.

The near-infrared conjugates deliver greater signal-to-noise ratios compared to visible-light fluorophores, supporting multiplex detection and higher sensitivity. The HRP-conjugated option allows seamless integration with chemiluminescent western blot workflows.

CD81 is a core member of the tetraspanin family (alongside CD9 and CD63), making it an essential marker for EV characterisation. This antibody complements ExoBrite™ CD9 and CD63 Western Antibodies to form a complete tetraspanin profiling toolkit.

Key Features

  • Validated for CD81 detection in EV western blots
  • Available in near-infrared fluorescent (680/700, 770/800) and HRP formats
  • Bright signal, low background for reliable EV analysis
  • Multiplex-ready with near-infrared channels
  • Complements ExoBrite™ CD9 and CD63 Western Antibodies for full EV marker profiling

 

Notes: Biotium products are available only in Singapore and Thailand.

 

Profile EVs with ExoBrite™ CD81 Western Antibody – available in fluorescent and HRP formats for reliable detection of tetraspanin CD81.

*Please leave us a message during checkout to indicate which kit you need, and our team will process your order accordingly.

Product Attributes

Attribute Details
Antibody number P006
SwissProt P60033
Antibody type Primary
Clonality Monoclonal
Host species Mouse
Isotype IgG1, kappa
Antibody reactivity (target) CD81
Synonyms CD81; TAPA-1; Tetraspanin-28; Tspan-28
Species reactivity Human, Baboon, Cynomolgus monkey, Non-human primates; Mouse (low reactivity)
Human gene symbol CD81
Entrez gene ID 975
Unigene 54457
Molecular weight 26 kDa
Target cellular localisation Exosomes/EVs, Plasma membrane
Cell/tissue expression Exosomes, Hepatocytes, Lymphocytes, Monocytes/Macrophages
Verified applications Western blot (fluorescent or chemiluminescent, verified)
Positive control MCF-7 cells, MCF-7 derived exosomes
Recommended use ~100 ng/mL (1:1000 dilution for WB, adjust as required by end-user)
Conjugate formulation Fluorescent conjugates: PBS, 0.1% BSA, 0.05% azide; HRP conjugates: PBS, 50% glycerol, 2 mg/mL rBSA
Volume per assay 10 µL/test
Shelf life ≥ 24 months from receipt (if stored as recommended)
Storage conditions Store at 2–8 °C, protect fluorescent conjugates from light
Shipping condition Room temperature
Regulatory status Research Use Only (RUO)
Product origin May contain BSA (bovine) or recombinant BSA (CHO cells). Inquire for lot-specific details.

Variations

Antibody Ex/Em (nm) Concentration Size Options Detection Channel Catalog No.
ExoBrite™ 680/700 CD81 Western Antibody 681/698 100 µg/mL 25 / 100 tests NIR (700 channel) P006-680-250 / P006-680-1000
ExoBrite™ 770/800 CD81 Western Antibody 770/797 100 µg/mL 25 / 100 tests NIR (800 channel) P006-770-250 / P006-770-1000

Documentation

Proven Performance

Chemiluminescent western detection of CD81 in 10 ug of HEK-293 whole cell lysate (non-reduced) using 25 ng/mL ExoBrite™ CD81-HRP conjugate, detected with SuperSignal™ West Femto Substrate (Thermo Fisher) and imaged on a LICORbio™ Odyssey® M imaging system.
Chemiluminescent western detection of CD81 in 10 ug of HEK-293 whole cell lysate (non-reduced) using 25 ng/mL ExoBrite™ CD81-HRP conjugate, detected with SuperSignal™ West Femto Substrate (Thermo Fisher) and imaged on a LICORbio™ Odyssey® M imaging system.
Western detection of human CD81 in cell and exosome lysate using ExoBrite™ 680/700 CD81 Western Antibody, showing enrichment of CD81 in the exosome prep. Exosomes were isolated from MCF-7 cell conditioned medium by size exclusion column. The indicated amounts of lysates from MCF-7 cells and MCF-7-derived exosomes were run on an acrylamide gel and transferred to PVDF. The membrane was blocked with TrueBlack® Western Blocking Buffer, stained with 1X ExoBrite™ 680/700 CD81 Western Antibody, and imaged on a LI-COR Odyssey® infrared imaging system in the 700 channel. The protein ladder is Peacock™ Prestained Protein Marker, 1.5 uL per lane.
Western detection of human CD81 in cell and exosome lysate using ExoBrite™ 680/700 CD81 Western Antibody, showing enrichment of CD81 in the exosome prep. Exosomes were isolated from MCF-7 cell conditioned medium by size exclusion column. The indicated amounts of lysates from MCF-7 cells and MCF-7-derived exosomes were run on an acrylamide gel and transferred to PVDF. The membrane was blocked with TrueBlack® Western Blocking Buffer, stained with 1X ExoBrite™ 680/700 CD81 Western Antibody, and imaged on a LI-COR Odyssey® infrared imaging system in the 700 channel. The protein ladder is Peacock™ Prestained Protein Marker, 1.5 uL per lane.
Western blot showing CD81 enrichment in exosomes using ExoBrite™ Western Antibodies in MCF-7 cell and exosome lysates. Exosomes were isolated from MCF-7 cell conditioned medium by size exclusion column. The indicated amounts of lysates from MCF-7 cells and MCF-7-derived exosomes were run on an acrylamide gel and transferred to PVDF. The membrane was blocked with TrueBlack® Western Blocking Buffer, stained with 1X ExoBrite™ 680/700 CD81 Western Antibody and 1X ExoBrite™ 770/800 Calnexin Western Antibody, and imaged on a LI-COR Odyssey® infrared imaging system in the 700 and 800 channels. The protein ladder is Peacock™ Prestained Protein Marker, 1.5 uL loaded.
Western blot showing CD81 enrichment in exosomes using ExoBrite™ Western Antibodies in MCF-7 cell and exosome lysates. Exosomes were isolated from MCF-7 cell conditioned medium by size exclusion column. The indicated amounts of lysates from MCF-7 cells and MCF-7-derived exosomes were run on an acrylamide gel and transferred to PVDF. The membrane was blocked with TrueBlack® Western Blocking Buffer, stained with 1X ExoBrite™ 680/700 CD81 Western Antibody and 1X ExoBrite™ 770/800 Calnexin Western Antibody, and imaged on a LI-COR Odyssey® infrared imaging system in the 700 and 800 channels. The protein ladder is Peacock™ Prestained Protein Marker, 1.5 uL loaded.
Western blot showing CD63 and CD81 enrichment in exosomes using ExoBrite™ Western Antibodies in MCF-7 cell and exosome lysates. Exosomes were isolated from MCF-7 cell conditioned medium by size exclusion column. The indicated amounts of lysates from MCF-7 cells and MCF-7-derived exosomes were run on an acrylamide gel and transferred to PVDF. The membrane was blocked with TrueBlack® Western Blocking Buffer, stained with 1X ExoBrite™ 680/700 CD81 Western Antibody and 1X ExoBrite™ 770/800 CD63 Western Antibody, and imaged on a LI-COR Odyssey® infrared imaging system in the 700 and 800 channels. The protein ladder is Peacock™ Plus Prestained Protein Marker, 1.5 uL loaded.
Western blot showing CD63 and CD81 enrichment in exosomes using ExoBrite™ Western Antibodies in MCF-7 cell and exosome lysates. Exosomes were isolated from MCF-7 cell conditioned medium by size exclusion column. The indicated amounts of lysates from MCF-7 cells and MCF-7-derived exosomes were run on an acrylamide gel and transferred to PVDF. The membrane was blocked with TrueBlack® Western Blocking Buffer, stained with 1X ExoBrite™ 680/700 CD81 Western Antibody and 1X ExoBrite™ 770/800 CD63 Western Antibody, and imaged on a LI-COR Odyssey® infrared imaging system in the 700 and 800 channels. The protein ladder is Peacock™ Plus Prestained Protein Marker, 1.5 uL loaded.
Chemiluminescent western detection of CD81 in 10 ug of HEK-293 whole cell lysate (non-reduced) using 25 ng/mL ExoBrite™ CD81-HRP conjugate, detected with SuperSignal™ West Femto Substrate (Thermo Fisher) and imaged on a LICORbio™ Odyssey® M imaging system.
Chemiluminescent western detection of CD81 in 10 ug of HEK-293 whole cell lysate (non-reduced) using 25 ng/mL ExoBrite™ CD81-HRP conjugate, detected with SuperSignal™ West Femto Substrate (Thermo Fisher) and imaged on a LICORbio™ Odyssey® M imaging system.
Western detection of human CD81 in cell and exosome lysate using ExoBrite™ 680/700 CD81 Western Antibody, showing enrichment of CD81 in the exosome prep. Exosomes were isolated from MCF-7 cell conditioned medium by size exclusion column. The indicated amounts of lysates from MCF-7 cells and MCF-7-derived exosomes were run on an acrylamide gel and transferred to PVDF. The membrane was blocked with TrueBlack® Western Blocking Buffer, stained with 1X ExoBrite™ 680/700 CD81 Western Antibody, and imaged on a LI-COR Odyssey® infrared imaging system in the 700 channel. The protein ladder is Peacock™ Prestained Protein Marker, 1.5 uL per lane.
Western detection of human CD81 in cell and exosome lysate using ExoBrite™ 680/700 CD81 Western Antibody, showing enrichment of CD81 in the exosome prep. Exosomes were isolated from MCF-7 cell conditioned medium by size exclusion column. The indicated amounts of lysates from MCF-7 cells and MCF-7-derived exosomes were run on an acrylamide gel and transferred to PVDF. The membrane was blocked with TrueBlack® Western Blocking Buffer, stained with 1X ExoBrite™ 680/700 CD81 Western Antibody, and imaged on a LI-COR Odyssey® infrared imaging system in the 700 channel. The protein ladder is Peacock™ Prestained Protein Marker, 1.5 uL per lane.
Western blot showing CD81 enrichment in exosomes using ExoBrite™ Western Antibodies in MCF-7 cell and exosome lysates. Exosomes were isolated from MCF-7 cell conditioned medium by size exclusion column. The indicated amounts of lysates from MCF-7 cells and MCF-7-derived exosomes were run on an acrylamide gel and transferred to PVDF. The membrane was blocked with TrueBlack® Western Blocking Buffer, stained with 1X ExoBrite™ 680/700 CD81 Western Antibody and 1X ExoBrite™ 770/800 Calnexin Western Antibody, and imaged on a LI-COR Odyssey® infrared imaging system in the 700 and 800 channels. The protein ladder is Peacock™ Prestained Protein Marker, 1.5 uL loaded.
Western blot showing CD81 enrichment in exosomes using ExoBrite™ Western Antibodies in MCF-7 cell and exosome lysates. Exosomes were isolated from MCF-7 cell conditioned medium by size exclusion column. The indicated amounts of lysates from MCF-7 cells and MCF-7-derived exosomes were run on an acrylamide gel and transferred to PVDF. The membrane was blocked with TrueBlack® Western Blocking Buffer, stained with 1X ExoBrite™ 680/700 CD81 Western Antibody and 1X ExoBrite™ 770/800 Calnexin Western Antibody, and imaged on a LI-COR Odyssey® infrared imaging system in the 700 and 800 channels. The protein ladder is Peacock™ Prestained Protein Marker, 1.5 uL loaded.
Western blot showing CD63 and CD81 enrichment in exosomes using ExoBrite™ Western Antibodies in MCF-7 cell and exosome lysates. Exosomes were isolated from MCF-7 cell conditioned medium by size exclusion column. The indicated amounts of lysates from MCF-7 cells and MCF-7-derived exosomes were run on an acrylamide gel and transferred to PVDF. The membrane was blocked with TrueBlack® Western Blocking Buffer, stained with 1X ExoBrite™ 680/700 CD81 Western Antibody and 1X ExoBrite™ 770/800 CD63 Western Antibody, and imaged on a LI-COR Odyssey® infrared imaging system in the 700 and 800 channels. The protein ladder is Peacock™ Plus Prestained Protein Marker, 1.5 uL loaded.
Western blot showing CD63 and CD81 enrichment in exosomes using ExoBrite™ Western Antibodies in MCF-7 cell and exosome lysates. Exosomes were isolated from MCF-7 cell conditioned medium by size exclusion column. The indicated amounts of lysates from MCF-7 cells and MCF-7-derived exosomes were run on an acrylamide gel and transferred to PVDF. The membrane was blocked with TrueBlack® Western Blocking Buffer, stained with 1X ExoBrite™ 680/700 CD81 Western Antibody and 1X ExoBrite™ 770/800 CD63 Western Antibody, and imaged on a LI-COR Odyssey® infrared imaging system in the 700 and 800 channels. The protein ladder is Peacock™ Plus Prestained Protein Marker, 1.5 uL loaded.