Aptamer Selection Express: A Rapid Single-Step Selection of Double- stranded DNA Capture Elements

摘要

SELEX: Advantages of Aptamers * Aptamers are smaller than antibodies -- ranging from 30 to 50 nucleotides * Do not require either animals or tissue culture for production * Can be synthesized chemically or by PCR * Due to the nature of DNA, they are stable in harsh environments and do not require special storage conditions * Offer additional chemistries and modalities for further stabilization (nuclease resistance) and assays. SELEX: Selection of Aptamers. Selection begins with a single strand of DNA. The target is bound to a filter, and a portion of the library binds to the target. The bound strands (+) are eluted from the target by heat and amplified using PCR, with the primer for the negative strand containing biotin at its 5' end. After amplification, the DNA is denatured and the (-) strands separated from the (+) strands by passing the DNA over a streptavidin column, which retains the biotin containing (-) strands. Another round of selection is begun.