In vitro selection of RNA aptamer to hemin.

A new RNA aptamer-binding hemin was synthesized by the in vitro selection (SELEX) method. A pool of 103 bases single strand DNAs containing a randomized sequence of 59 bases was synthesized. The pool was incubated with hemin on hemin-immobilized affinity column. Bound RNAs were eluted off with hemin solution and amplified by PCR. After 3 rounds of selection process, the selected RNAs were cloned and sequenced. Some RNA aptamers, which have affinity to hemin, was selected.