SINGLE STRANDED DNA APTAMERS SPECIFICALLY BINDING TO E. COLI O157:H7 AND PRODUCTION METHOD THEREOF

摘要

Disclosed are a single stranded DNA aptamer specifically binding to E. coli O157:H7 and a production method thereof. The method for producing the aptamer comprises systematic evolution of ligands by exponential enrichment (SELEX) and counter SELEX processes. The SELEX process includes the following steps: inducing E. Coli O157:H7-DNA conjugates by mixing a DNA library, including DNAs which have primer areas for PCR on both ends thereof and 40 randomly-arranged nucleotides on the center thereof, and the E. Coli O157:H7 with a conjugation buffer solution (S1); extracting the E. Coli O157:H7-DNA conjugates by centrifuging a mixture solution of the DNA library and the E. Coli O157:H7 (S2); separating DNAs from the Salmonella-DNA conjugate (S3); and amplifying the separated DNAs by polymerase chain reaction (S4). The counter SELEX process comprises the steps of: inducing non-target microorganism-DNA conjugates by mixing the amplified DNAs and a non-target microorganism with a conjugation buffer solution (S5); and extracting DNAs, which are not bound with the non-target microorganism by centrifuging a mixture solution of the concentrated DNAs and the non-target microorganism (S6). After repeating the SELEX process five times, the counter SELEX process is performed once. And then, alternative performance of the SELEX and counter SELEX processes is repeated twice.