Correlation Engine 2.0
Clear Search sequence regions

Sizes of these terms reflect their relevance to your search.

The need for pre-analytical sample processing prior to the application of rapid molecular-based detection of pathogens in food and environmental samples is well established. Although immunocapture has been applied in this regard, alternative ligands such as nucleic acid aptamers have advantages over antibodies such as low cost, ease of production and modification, and comparable stability. To identify DNA aptamers demonstrating binding specificity to Campylobacter jejuni cells, a whole-cell Systemic Evolution of Ligands by EXponential enrichment (SELEX) method was applied to a combinatorial library of FAM-labeled single-stranded DNA molecules. FAM-labeled aptamer sequences with high binding affinity to C. jejuni A9a as determined by flow cytometric analysis were identified. Aptamer ONS-23, which showed particularly high binding affinity in preliminary studies, was chosen for further characterization. This aptamer displayed a dissociation constant (K(d) value) of 292.8 +/- 53.1 nM with 47.27 +/- 5.58% cells fluorescent (bound) in a 1.48-microM aptamer solution. Binding assays to assess the specificity of aptamer ONS-23 showed high binding affinity (25-36%) for all other C. jejuni strains screened (inclusivity) and low apparent binding affinity (1-5%) with non-C. jejuni strains (exclusivity). Whole-cell SELEX is a promising technique to design aptamer-based molecular probes for microbial pathogens without tedious isolation and purification of complex markers or targets.


Hari P Dwivedi, R Derike Smiley, Lee-Ann Jaykus. Selection and characterization of DNA aptamers with binding selectivity to Campylobacter jejuni using whole-cell SELEX. Applied microbiology and biotechnology. 2010 Aug;87(6):2323-34

Expand section icon Mesh Tags

Expand section icon Substances

PMID: 20582587

View Full Text