Escherichia coli O157:H7, E.coli O157:H7 ELISA Kit

Catalog No.: BEK1249

Size: 96T

Range: 6.25 × 10³ cfu/ml - 4 ×10⁵ cfu/ml

Sensitivity < 1 ×10³ cfu/ml

Specificity: No cross react with other cytokines

Storage and Expiration: Store at 2-8℃ for 6 months, or at -20℃ for 12 months. Store HRP conjugated antibody at 2-8℃.

Application: For quantitative detection of E.coli O157:H7 in food or water. 

Introduction

Escherichia coli O157:H7 is an enterohemorrhagic serotype of the bacterium Escherichia coli and a cause of illness, typically through consumption of contaminated food. As an emerging pathogen, Escherichia coli O157:H7 causes severe enteritis and the extraintestinal complication of hemolytic-uremic syndrome. Rokhsartalab-Azar S et al evaluate the conjugate of E. coli O157: H7 lipopolysaccharide (LPS) with diphtheria toxoid (DT) as a candidate vaccine in mice model. Their results showed that the suggested vaccine composed of E. coli O157:H7 LPS and DT had a significant potential to protect against E. coli infections. Infection with Escherichia coli O157:H7 may develop into hemorrhagic colitis, or hemolytic uremic syndrome (HUS), which usually causes kidney failure or even death. The adhesion and toxins are the important virulent factors. Cai K et al constructed a novel vaccine candidate rSOBGs based on the bacterial ghost (BG). They found the novel vaccine candidate rSOBGs induced both anti-toxin and anti-adhesion immune protection, suggesting the possibility to prevent the infectious diseases caused by Escherichia coli O157:H7.

Principle of the Assay  

This kit was based on sandwich enzyme-linked immune-sorbent assay technology. Anti-E.coli O157:H7 monoclonal antibody was pre-coated onto 96-well plates. And the HRP conjugated anti-E.coli O157:H7 polyclonal antibody was used as detection antibodies. The standards, test samples and HRP conjugated detection antibody were added to the wells subsequently, and wash with wash buffer. TMB substrates were used to visualize HRP enzymatic reaction. TMB was catalyzed by HRP to produce a blue color product that changed into yellow after adding acidic stop solution. The density of yellow is proportional to the E.coli O157:H7 amount of sample captured in plate. Read the O.D. absorbance at 450nm in a microplate reader, and then the concentration of E.coli O157:H7 can be calculated.

Kit components

1. One 96-well plate pre-coated with anti-E.coli O157:H7 antibody
2. Lyophilized E.coli O157:H7 standards: 2 tubes (4 × 10⁵ cfu / tube)
3. Sample diluent buffer: 30 ml                         
4. HRP conjugated anti-E.coli O157:H7 antibody (Concentrated): 130 μl. Dilution: 1:100 
5. Antibody diluent buffer: 12 ml
6. TMB substrate: 10 ml
7. Stop solution: 10 ml
8. Wash buffer: 30 ml (25x). Dilution: 1:25

Note: Reconstitute standards and test samples with Kit Component 3.

Material Required But Not Provided

1. Microplate reader (wavelength: 450nm)
2. Precise pipette and disposable pipette tips
3. Automated plate washer
4. ELISA shaker
5. 1.5ml of Eppendorf tubes
6. Plate cover
7. Absorbent filter papers
8. Plastic or glass container with volume of above 1L