Toll-like receptor 9 ELISA Kit (TLR9)

Full Name: Toll-like receptor 9 ELISA Kit (TLR9)
Reactivity: Human
Sample Type: Plasma, Tissue Homogenates, Serum, Biological Fluids
Sensitivity: 0.094 ng/ml


LR9, or Toll-like receptor 9, is an important receptor involved in the innate immune system’s detection of pathogens and activation of defensive immune responses. Found in immune cells such as macrophages and dendritic cells, TLR9 specifically recognizes unmethylated CpG dinucleotides, which are DNA motifs frequently present in bacteria and viruses but less common in vertebrate cells. The stimulation of TLR9 by these pathogen-associated molecular patterns leads to signaling cascades that prompt immune cells to mount defensive reactions.

Through intracellular signaling after TLR9 activation, immune cells produce inflammatory cytokines and interferons that combat pathogens and infected cells. Excessive stimulation of TLR9 however can result in chronic inflammation or autoimmunity if not properly regulated. The receptor interacts with the adaptor protein MyD88 to elicit these immunological effects after detecting foreign CpG DNA from infecting pathogens ingested into endosomes within immune cells. Synthetic CpG oligonucleotides can also be used to deliberately activate TLR9 for research purposes or to boost immune responses in medical applications.

While TLR9 is an intracellular receptor in humans, mice express it on the cell surface as well, indicating slightly different immunity roles between species. ​Enhanced knowledge of this receptor could lead to improved infectious disease treatments, vaccines utilizing CpG oligonucleotides as adjuvants, and immunotherapies that beneficially stimulate natural TLR9 activity to strengthen desirable immune responses.


Human toll-like receptor 9 ELISA kit can measure concentrations of TLR9 (toll-like receptor 9, CD289) present is plasma, serum, biological fluids or tissue homogenate samples.


All reagents supplied need to be stored at 2 °C – 8 °C, unopened reagents will retain reactivity until expiration date. Do not use reagents beyond this date.

  • One 96-Well Plate: Pre-coated with anti- TLR9.
  • Standards: Lyophilized recombinant.
  • Sample/Standard Dilution Buffer.
  • Biotinylated-labelled Antibody.
  • Antibody Dilution Buffer.
  • HRP-Streptavidin Conjugate (SABC).
  • SABC Dilution Buffer.
  • TMB Substrate.
  • Wash Buffer (25x).
  • Plate Sealer.
  • Product Instructions.


For this toll-like receptor 9 ELISA kit, it is recommended that a standard curve is generated for each assay carried out.

Standard Curve: 0, 0.156, 0.312, 0.625, 1.25, 2.5, 5, 10 ng/ml.
Reactivity: Human
Sensitivity: 0.094 ng/ml
Range: 0.156 – 10 ng/ml
Principle: Sandwich, Double Antibody
Application: Research Use Only.


– Specificity: Highly specific for TLR9, no cross reactivity or interference between TLR9 and analogues was detected.
– Recovery: Serum (89 – 100%), EDTA Plasma (88 – 105%), Heparin Plasma (86 – 104%).
– Linearity: Serum (95 – 103%), EDTA Plasma (84 – 93%), Heparin Plasma (88 – 97%).
– Precison Intra-Assay: CV < 8%
– Precison Inter-Assay: CV < 10%


  1. Toll-like receptor 9 signaling in chronic lymphocytic leukemia cell lines. FEBS Open Bio. (2023) 13 (12): 2367-2374. Meloni M., et al.
  2. Genetic dissection of TLR9 reveals complex regulatory and cryptic proinflammatory roles in mouse lupus. Nat Immunol. (2022) 23 (10): 1457-1469. Leibler C., et al.
  3. TLR9-mediated recognition of DNA. Handb Exp Pharmacol. (2008) (183): 51-70. Müller T., et al.
  4. Toll-like receptor 9 (TLR9) agonists in the treatment of cancer. Oncogene. (2008) 27 (2): 161-7. Krieg A.M.


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