What is TOP purification and what can it be used for?
TOP: Trityl-On Oligonucleotide Purification TOP is a simple, high-throughput approach to oligonucleotide purification. TOP provides greater than 90% pure full-length oligo and is ideal for applications that require high-quality DNA. It efficiently removes truncated failure sequences generated during the synthesis process that do not contain a 5′ dimethoxytrityl group. In addition, deprotection solution salts and by-products (i.e. benzamide protecting groups) are also removed simultaneously. TOP chemistry is based on the principle of reverse-phase (RP) chromatography. Oligonucleotides purified by TOP are synthesized with the final 5′ terminus protecting group [trityl or dimethoxyltrityl (DMT)] left on the oligo. The hydrophobic nature of the trityl group permits tighter retention of the desired full-length oligo than the truncated failure sequences that do not contain a trityl group. The failure sequences are washed from the tube with a low percent acetonitrile rinse. Retained oligonucl
