Further characterization and independent validation of a DNA aptamer-quantum dot-based magnetic sandwich assay for Campylobacter.
Previously reported DNA aptamers developed against surface proteins extracted from Campylobacter jejuni were further characterized by aptamer-based Western blotting and shown to bind epitopes on proteins weighing ~16 and 60 kD from reduced C. jejuni and Campylobacter coli lysates. Proteins of these approximate weights have also been identified in traditional antibody-based Western blots of Campylobacter spp. Specificity of the capture and reporter aptamers from the previous report was further validated by aptamer-based ELISA-like (ELASA) colorimetric microplate assay. Finally, the limit of detection of the previously reported plastic-adherent aptamer-magnetic bead and aptamer-quantum dot sandwich assay (PASA) was validated by an independent food safety testing laboratory to lie between 5 and 10 C. jejuni cells per milliliter in phosphate buffered saline and repeatedly frozen and thawed chicken rinsate. Such ultrasensitive and rapid (30 min) aptamer-based assays could provide alternative or additional screening tools to enhance food safety testing for Campylobacter and other foodborne pathogens.
Operational Technologies Corporation, 4100 NW Loop 410, Suite 230, San Antonio, TX, 78229, USA. john.bruno@otcorp.com.
John G
JG
Bruno
Operational Technologies Corporation, 4100 NW Loop 410, Suite 230, San Antonio, TX, 78229, USA.
Jeffrey C
JC
Sivils
D000818:Animals; D052157:Aptamers, Nucleotide / Q000235:genetics; D001681:Biological Assay / Q000295:instrumentation / Q000379:methods*; D002167:Campylobacter / Q000235:genetics / Q000302:isolation & purification*; D002645:Chickens; D005506:Food Contamination / Q000032:analysis*; D008280:Magnetics / Q000379:methods*; D008460:Meat / Q000382:microbiology*; D045663:Quantum Dots / Q000737:chemistry
D052157:Aptamers, Nucleotide
External Magnet; Foodborne Pathogen; Sandwich Assay; Small Detection Area; Sterile Buffer