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TLR4 Antibody (76B357.1) - BSA Free

Catalog # NB100-56566 | Novus Biologicals a Bio-Techne Brand
Catalog #
Size / Price

Key Product Details

Validated by

Orthogonal Validation

Species Reactivity

Human, Mouse, Rat, Porcine, Bovine, Mammal


Block/Neutralize, Chromatin Immunoprecipitation (ChIP), CyTOF-ready, Dot Blot, Dual RNAscope ISH-IHC, ELISA, ELISA Capture (Matched Antibody Pair), Flow (Cell Surface), Flow (Intracellular), Flow Cytometry, Immunocytochemistry/ Immunofluorescence, Immunohistochemistry, Immunohistochemistry-Frozen, Immunohistochemistry-Paraffin, In vitro assay, Knockdown Validated, Knockout Validated, SDS-Page, Western Blot



Antibody Source

Monoclonal Mouse IgG2b Kappa Clone # 76B357.1


BSA Free


1.0 mg/ml

Product Summary for TLR4 Antibody (76B357.1) - BSA Free


This TLR4 Antibody (76B357.1) was developed against a portion of amino acids 100-200 of human TLR4 (NP_612564).

Predicted Species

Baboon (100%), Chinese Hamster (100%). Backed by our 100% Guarantee.






IgG2b Kappa

Theoretical MW

95.7 kDa.
Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors.

Scientific Data Images for TLR4 Antibody (76B357.1) - BSA Free

Dual RNAscope ISH-IHC: TLR4 Antibody (76B357.1) [NB100-56566] - FFPE tissue sections of human tonsil were probed for TLR4 mRNA (ACD RNAScope Probe, ACD catalog # 311281; Fast Red chromogen, ACD catalog # 322750). Adjacent tissue section was processed for immunohistochemistry using Mouse Monoclonal (Novus Biologicals catalog # NB100-56566) at 5ug/mL with 1 hour incubation at room temperature followed by incubation with anti-mouse IgG VisUCyte HRP Polymer Antibody (Catalog # VC001) and DAB chromogen (yellow-brown). Tissue was counterstained with hematoxylin (blue). Specific staining was localized to lymphocytes.
Flow Cytometry: TLR4 Antibody (76B357.1) [NB100-56566] - Analysis using the Alexa Fluor (R) 647 conjugate of NBP2-27149. TLR4 expression on monocytes from human peripheral blood. PBMC were stained in a 2 color flow test, with CD14 PE version of this antibody and 1 ug of either isotype control (left) or TLR4-Alexa Fluor 647 (right). PPI negative, CD14+ cells were gated for analysis.
Immunohistochemistry: TLR4 Antibody (76B357.1) [NB100-56566] - Pericryptal Myofibroblasts are Responsible for Increased TLR4 Expression in a Subset of CRCs. Double-stained immunofluorescence for TLR4 (green) and vimentin (red) in normal (I), adenoma (II), and colon adenocarcinoma (III) (10x). In the stromal compartment of CRCs, immunofluorescent staining for TLR4 localized to the pericryptal myofibroblasts in a subset of samples. Image collected and cropped by CiteAb from the following publication (, licensed under a CC-BY license.

Applications for TLR4 Antibody (76B357.1) - BSA Free

Recommended Usage

Chromatin Immunoprecipitation (ChIP)


ELISA Capture (Matched Antibody Pair)

0.5 ug

Immunocytochemistry/ Immunofluorescence







5 ug/ml


reported in scientific literature (PMID 33166339)

Western Blot

1-3 ug/ml
Please Note: Optimal dilutions of this antibody should be experimentally determined.

Reviewed Applications

Read 5 reviews rated 4.2 using NB100-56566 in the following applications:

Published Applications

Read 135 publications using NB100-56566 in the following applications:

Formulation, Preparation, and Storage


Protein G purified




BSA Free


0.05% Sodium Azide


1.0 mg/ml


The product is shipped with polar packs. Upon receipt, store it immediately at the temperature recommended below.

Stability & Storage

Store at 4C short term. Aliquot and store at -20C long term. Avoid freeze-thaw cycles.

Background: TLR4

TLR4 (Toll-like receptor 4) is a type-1 transmembrane glycoprotein that is a pattern recognition receptor (PRR) belonging to the TLR family (1-3). TLR4 is expressed in many tissues and is most abundantly expressed in the placenta, spleen, and peripheral blood leukocytes (1). Human TLR4 is synthesized as a 839 amino acid (aa) protein containing a signal sequence (1-23 aa), an extracellular domain (ECD) (24-631 aa), a transmembrane domain (632-652 aa), and Toll/interleukin-1 receptor (TIR) cytoplasmic domain (652-839 aa) with a theoretical molecular weight of 95 kDa (3, 4). The ECD contains 21 leucine-rich repeats (LRRs) and has a horseshoe-shaped structure (3, 4). TLR4 requires binding with the co-receptor myeloid differentiation protein 2 (MD2) largely via hydrophilic interactions for proper ligand sensing and signaling (2-4). In general, the TLR family plays a role in activation of innate immunity and responds to a variety of pathogen-associated molecular patterns (PAMPs) (5). TLR4 is specifically responsive to lipopolysaccharide (LPS), which is found on the outer-membrane of most ram-negative bacteria (3-5). Activation of TLR4 requires binding of a ligand, such as LPS to MD2, followed by MD2-LPS complex binding to TLR4, resulting in a partial complex (TLR4-MD2/LPS) (3, 5). To become fully active, two partial complexes must dimerize thereby allowing the TIR domains of TLR4 to bind other adapter molecular and initiate signaling, triggering an inflammatory response and cytokine production (3, 5).

TLR4 signaling occurs through two distinct pathways: The MyD88 (myeloid differentiation primary response gene 88)-dependent pathway and the MyD88-independent (TRIF-dependent, TIR domain-containing adaptor inducing IFN-beta) pathway (3, 5-7). The MyD88-dependent pathway occurs mainly at the plasma membrane and involves the binding of MyD88-adaptor-like (MAL) protein followed by a signaling cascade that results in the activation of transcription factors including nuclear factor-kappaB (NF-kappaB) that promote the secretion of inflammatory molecules and increased phagocytosis (5-7). Conversely, the MyD88-independent pathway occurs after TLR4-MD2 complex internalization in the endosomal compartment. This pathway involves the binding of adapter proteins TRIF and TRIF-related adaptor molecule (TRAM), a signaling activation cascade resulting in IFN regulatory factor 3 (IRF3) translocation into the nucleus, and secretion of interferon-beta (INF-beta) genes and increased phagocytosis (5-7).

Given its expression on immune-related cells and its role in inflammation, TLR4 activation can contribute to various diseases (6-8). For instance, several studies have found that TLR4 activation is associated with neurodegeneration and several central nervous system (CNS) pathologies, including Alzheimer's disease, Parkinson's disease, and Huntington's disease (6, 7). Furthermore, TLR4 mutations have been shown to lead to higher rates of infections and increased susceptibility to sepsis (7-8). One potential therapeutic approach aimed at targeting TLR4 and neuroinflammation is polyphenolic compounds which include flavonoids and phenolic acids and alcohols (8).

Alternative names for TLR4 includes 76B357.1, ARMD10, CD284 antigen, CD284, EC, homolog of Drosophila toll, hToll, toll like receptor 4 protein, TOLL, toll-like receptor 4.


1. Vaure, C., & Liu, Y. (2014). A comparative review of toll-like receptor 4 expression and functionality in different animal species. Frontiers in immunology.

2. Park, B. S., & Lee, J. O. (2013). Recognition of lipopolysaccharide pattern by TLR4 complexes. Experimental & molecular medicine.

3. Krishnan, J., Anwar, M.A., & Choi, S. (2016) TLR4 (Toll-Like Receptor 4). In: Choi S. (eds) Encyclopedia of Signaling Molecules. Springer, New York, NY.

4. Botos, I., Segal, D. M., & Davies, D. R. (2011). The structural biology of Toll-like receptors. Structure.

5. Lu, Y. C., Yeh, W. C., & Ohashi, P. S. (2008). LPS/TLR4 signal transduction pathway. Cytokine.

6. Leitner, G. R., Wenzel, T. J., Marshall, N., Gates, E. J., & Klegeris, A. (2019). Targeting toll-like receptor 4 to modulate neuroinflammation in central nervous system disorders. Expert opinion on therapeutic targets.

7. Molteni, M., Gemma, S., & Rossetti, C. (2016). The Role of Toll-Like Receptor 4 in Infectious and Noninfectious Inflammation. Mediators of inflammation.

8. Rahimifard, M., Maqbool, F., Moeini-Nodeh, S., Niaz, K., Abdollahi, M., Braidy, N., Nabavi, S. M., & Nabavi, S. F. (2017). Targeting the TLR4 signaling pathway by polyphenols: A novel therapeutic strategy for neuroinflammation. Ageing research reviews.

Long Name

Toll-like Receptor 4

Alternate Names

CD284, 76B357.1, tlr4 76B357.1, TLR4 facs, TLR4 flow cytometry, TLR4 human, TLR4 ihc, TLR4 western blot

Entrez Gene IDs

7099 (Human); 21898 (Mouse); 29260 (Rat)

Gene Symbol



Product Documents for TLR4 Antibody (76B357.1) - BSA Free

Certificate of Analysis

To download a Certificate of Analysis, please enter a lot number in the search box below.

Product Specific Notices for TLR4 Antibody (76B357.1) - BSA Free

This product is for research use only and is not approved for use in humans or in clinical diagnosis. Primary Antibodies are guaranteed for 1 year from date of receipt.



View specific protocols for TLR4 Antibody (76B357.1) - BSA Free (NB100-56566):

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Protocol for Flow Cytometry Intracellular Staining
Sample Preparation.
1. Grow cells to 60-85% confluency. Flow cytometry requires between 2 x 105 and 1 x 106 cells for optimal performance.
2. If cells are adherent, harvest gently by washing once with staining buffer and then scraping. Avoid using trypsin as this can disrupt certain epitopes of interest. If enzymatic harvest is required, use Accutase, Collagenase, or TrypLE Express for a less damaging option.
3. Reserve 100 uL for counting, then transfer cell volume into a 50 mL conical tube and centrifuge for 8 minutes at 400 RCF.
a. Count cells using a hemocytometer and a 1:1 trypan blue exclusion stain to determine cell viability before starting the flow protocol. If cells appear blue, do not proceed.
4. Re-suspend cells to a concentration of 1 x 106 cells/mL in staining buffer (NBP2-26247).
5. Aliquot out 100 uL samples in accordance with your experimental samples.

Tip: When cell surface and intracellular staining are required in the same sample, it is advisable that the cell surface staining be performed first since the fixation and permeablization steps might reduce the availability of surface antigens.

Intracellular Staining.
Tip: When performing intracellular staining, it is important to use appropriate fixation and permeabilization reagents based upon the target and its subcellular location. Generally, our Intracellular Flow Assay Kit (NBP2-29450) is a good place to start as it contains an optimized combination of reagents for intracellular staining as well as an inhibitor of intracellular protein transport (necessary if staining secreted proteins). Certain targets may require more gentle or transient permeabilization protocols such as the commonly employed methanol or saponin-based methods.
Protocol for Cytoplasmic Targets:
1. Fix the cells by adding 100 uL fixation solution (such as 4% PFA) to each sample for 10-15 minutes.
2. Permeabilize cells by adding 100 uL of a permeabization buffer to every 1 x 106 cells present in the sample. Mix well and incubate at room temperature for 15 minutes.
a. For cytoplasmic targets, use a gentle permeabilization solution such as 1X PBS + 0.5% Saponin or 1X PBS + 0.5% Tween-20.
b. To maintain the permeabilized state throughout your experiment, use staining buffer + 0.1% of the permeabilization reagent (i.e. 0.1% Tween-20 or 0.1% Saponin).
3. Following the 15 minute incubation, add 2 mL of the staining buffer + 0.1% permeabilizer to each sample.
4. Centrifuge for 1 minute at 400 RCF.
5. Discard supernatant and re-suspend in 100 uL of staining buffer + 0.1% permeabilizer.
6. Add appropriate amount of each antibody (eg. 1 test or 1 ug per sample, as experimentally determined).
7. Mix well and incubate at room temperature for 30 minutes- 1 hour. Gently mix samples every 10-15 minutes.
8. Following the primary/conjugate incubation, add 1-2 mL/sample of staining buffer +0.1% permeabilizer and centrifuge for 1 minute at 400 RCF.
9. Wash twice by re-suspending cells in staining buffer (2 mL for tubes or 200 uL for wells) and centrifuging at 400 RCF for 5 minutes. Discard supernatant.
10. Add appropriate amount of secondary antibody (as experimentally determined) to each sample.
11. Incubate at room temperature in dark for 20 minutes.
12. Add 1-2 mL of staining buffer and centrifuge at 400 RCF for 1 minute and discard supernatant.
13. Wash twice by re-suspending cells in staining buffer (2 mL for tubes or 200 uL for wells) and centrifuging at 400 RCF for 5 minutes. Discard supernatant.
14. Resuspend in an appropriate volume of staining buffer (usually 500 uL per sample) and proceed with analysis on your flow cytometer.

Immunocytochemistry Protocol

Culture cells to appropriate density in 35 mm culture dishes or 6-well plates.

1. Remove culture medium and wash the cells briefly in PBS. Add 10% formalin to the dish and fix at room temperature for 10 minutes.
2. Remove the formalin and wash the cells in PBS.
3. Permeablize the cells with 0.1% Triton X100 or other suitable detergent for 10 min.
4. Remove the permeablization buffer and wash three times for 10 minutes each in PBS. Be sure to not let the specimen dry out.
5. To block nonspecific antibody binding, incubate in 10% normal goat serum from 1 hour to overnight at room temperature.
6. Add primary antibody at appropriate dilution and incubate overnight at 4C.
7. Remove primary antibody and replace with PBS. Wash three times for 10 minutes each.
8. Add secondary antibody at appropriate dilution. Incubate for 1 hour at room temperature.
9. Remove secondary antibody and replace with PBS. Wash three times for 10 minutes each.
10. Counter stain DNA with DAPi if required.
Immunohistochemistry-Paraffin Embedded Sections

Antigen Unmasking:
Bring slides to a boil in 10 mM sodium citrate buffer (pH 6.0) then maintain at a sub-boiling temperature for 10 minutes. Cool slides on bench-top for 30 minutes (keep slides in the sodium citrate buffer all the time).

1. Wash sections in deionized water three times for 5 minutes each.
2. Wash sections in PBS for 5 minutes.
3. Block each section with 100-400 ul blocking solution (1% BSA in PBS) for 1 hour at room temperature.
4. Remove blocking solution and add 100-400 ul diluted primary antibody. Incubate overnight at 4 C.
5. Remove antibody solution and wash sections in wash buffer three times for 5 minutes each.
6. Add 100-400 ul HRP polymer conjugated secondary antibody. Incubate 30 minutes at room temperature.
7. Wash sections three times in wash buffer for 5 minutes each.
8. Add 100-400 ul DAB substrate to each section and monitor staining closely.
9. As soon as the sections develop, immerse slides in deionized water.
10. Counterstain sections in hematoxylin.
11. Wash sections in deionized water two times for 5 minutes each.
12. Dehydrate sections.
13. Mount coverslips.
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Western Blot Protocol

1. Perform SDS-PAGE on samples to be analyzed, loading 10-25 ug of total protein per lane.
2. Transfer proteins to PVDF membrane according to the instructions provided by the manufacturer of the membrane and transfer apparatus.
3. Stain the membrane with Ponceau S (or similar product) to assess transfer success, and mark molecular weight standards where appropriate.
4. Rinse the blot TBS -0.05% Tween 20 (TBST).
5. Block the membrane in 5% Non-fat milk in TBST (blocking buffer) for at least 1 hour.
6. Wash the membrane in TBST three times for 10 minutes each.
7. Dilute anti-TLR4 primary antibody in blocking buffer and incubate overnight at 4C with gentle rocking.
8. Wash the membrane in TBST three times for 10 minutes each.
9. Incubate the membrane in diluted HRP conjugated secondary antibody in blocking buffer (as per manufacturer's instructions) for 1 hour at room temperature.
10. Wash the blot in TBST three times for 10 minutes each (this step can be repeated as required to reduce background).
11. Apply the detection reagent of choice in accordance with the manufacturers instructions.

FAQs for TLR4 Antibody (76B357.1) - BSA Free

Showing  1 - 5 of 5 FAQs Showing All
  • Q: I want to check the TLR4 expression on Swine embryonic fibroblast cells. Is it applicable to use this human TLR4 antibody? Have you obtained any results on swine cells using this TLR4 antibody.

    A: This antibody has not been used on swine however I have carried out a blast and the % homology is 73% between the human protein and the pig protein. If you would be interested in testing this novel species, please take a look at our Innovators Reward Program.

  • Q: Do you know the amino acid sequence against which this antibody is directed to? Also, what isoform of the protein would it be recognizing, or from what specific TLR4 transcript?

    A: This antibody binds within amino acids 100-200 of TLR4. This antibody will recognize isoforms 1 and 2 of TLR4 as this region is present in both of these isoforms, but not isoform 3, according to UniProt O00206.

  • Q: Would you be able to share the sequence homology/alignment of the immunogen sequence of NB100-56566 to the Zebrafish protein (Uniprot S5Q1H4)?

    A: We ran the sequence you provided against the immunogen, and unfortunately, there is only a 28% homology.

  • Q: I would like to use this antibody but it has not been validated in my species of interest. Is there any way I can find out if it will work?

    A: We offer risk-free testing of all of our primary antibodies. Please check out our Innovator's Reward Program and test this TLR4 antibody in any unvalidated species or application, without the financial risk of failure.

  • Q: How do I choose secondary antibodies to label the same cells when I have two primary antibodies from the same host?

    A: Use isotype-specific secondary antibodies if the primary antibodies are of different isotypes. You can also make direct conjugates of the primary antibodies by use of antibody labeling kits, dyes, or custom conjugations (please contact Technical Support for custom orders).

Showing  1 - 5 of 5 FAQs Showing All