Abstract
In vitro run-off transcription from a double-stranded DNA template by T7 RNA polymerase is an elegant way to obtain highly pure and uniform RNA oligonucleotides of lengths ranging from about 15 to several thousand nucleotides. Here we describe the different strategies applied and optimized in our laboratory to enzymatically synthesize RNAs as necessary when working at the interface of bioinorganic chemistry, coordination chemistry, RNA biochemistry and structural biology.