FLA-BS (Standard or Ultrapure)

Purified Flagellin from Bacillus subtilis

FLA-BS, a ~32 kDa protein, is a flagellin isolated from the Gram-positive bacteria Bacillus subtilis.

InvivoGen provides FLA-BS with two grades of purity:
• FLA-BS was purified by acid hydrolysis, heating and ultrafiltration.
• FLA-BS Ultrapure extracted by violent agitation and purified by different successive separation techniques. The purity of FLA-BS Ultrapure is greater than 95% as determined by SDS-PAGE.


Specificity: TLR5 agonist
Solubility: 0.5 mg/ml in water
Endotoxin level: <0.05 EU/µg

Working Concentration: 10 ng - 10 μg/ml
Purity: ≈ 10%

FLA-BS Ultrapure
Working Concentration: 1 ng -1 μg/ml
Purity: > 95%


• 100 μg FLA-BS (flagellin from B.subtilis)
• 1.5 ml endotoxin-free water

FLA-BS Ultrapure
• 50 μg FLA-BS Ultrapure (purified flagellin from B.subtilis)
• 1.5 ml endotoxin-free water

FLA-BS is shipped at room temperature and should be stored at -20°C. Upon resuspension, prepare aliquots of FLA-BS and store at -20°C. Resuspended product is stable for 6 months at -20°C when properly stored. Avoid repeated freeze-thaw cycles.


Flagellin, the principal component of the flagella present on many Gram-negative and Gram-positive bacteria, is a proinflammatory molecule recognized by distinct types of pattern recognition receptors (PRRs); the surface localized Toll-like receptor (TLR5) [1] and the cytosolic NOD-like receptors (NLRs), NLRC4 and NAIP5 [2].

Extracellular flagellin is detected by TLR5 resulting in MyD88-mediated NF-κB activation, cytokine and nitric oxide production depending on the nature of the TLR5 signaling complex [3].
Intracellular flagellin is detected by NLRC4 (also known as IPAF) and NAIP5. Recognition by NLRC4 and NAIP5, leads to inflammasome assembly, triggering caspase-1 activation of IL-1β and IL-18.

1. Hayashi f. et al., 2001. The innate immune response to bacterial flagellin is mediated by Toll-like receptor 5. Nature 410(6832):1099-103.
2. Zhao et al., 2011. The NLRC4 inflammasome receptors for bacterial flagellin and type III secretion apparatus. Nature. 2011 Sep 14;477(7366):596-600.
3. mizel SB. et al., 2003. Induction of macrophage nitric oxide production by Gram-negative flagellin involves signaling via heteromeric Toll-like receptor 5/Toll-like receptor 4 complexes. J Immunol. 170(12):6217-23.


Recent articles using InvivoGen FLA-BS (Standard or Ultrapure)


FLA-BS Ultrapure

Description Ultrapure flagellin from B . subtilis
Cat. Codetlrl-pbsfla
Unit Size50 µg
Price For price or distributor address,
please select your country


Description Standard flagellin from B. subtilis
Cat. Codetlrl-bsfla
Unit Size100 µg
Price For price or distributor address,
please select your country
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