title: RNA aptamers and spiegelmers: synthesis, purification, and post-synthetic PEG conjugation.
abstract: This unit describes the solid-phase synthesis and downstream processing for RNA oligonucleotides with a length of up to 40 to 50 nucleotides on a 1- to 4-mmol scale with subsequent conjugation to PEG using the L-RNA spiegelmer NOX-E36 as an example. Following synthesis and two-step deprotection, the crude oligonucleotide is purified by preparative reversed-phase HPLC and desalted by tangential flow ultrafiltration. The resulting intermediate amino-modified oligonucleotide is reacted with NHS-ester-activated PEG, and the oligonucleotide-PEG conjugate is obtained after preparative AX-HPLC purification, followed by ultrafiltration and lyophilization. Critical process parameters are described, as well as time considerations and examples for analytical methods used as in-process and quality controls.
authors: NOXXON Pharma AG, Berlin, Germany.
authors: Stefanie
authors: S
authors: Hoffmann
authors: Johannes
authors: J
authors: Hoos
authors: Sven
authors: S
authors: Klussmann
authors: Stefan
authors: S
authors: Vonhoff
mesh_terms: D052157:Aptamers, Nucleotide / Q000138:chemical synthesis* / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid; D005612:Freeze Drying; D009841:Oligonucleotides / Q000737:chemistry / Q000302:isolation & purification; D054735:Phosphorothioate Oligonucleotides / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D060327:Solid-Phase Synthesis Techniques; D014462:Ultrafiltration
chemical_list: D052157:Aptamers, Nucleotide; D009841:Oligonucleotides; D054735:Phosphorothioate Oligonucleotides; D011092:Polyethylene Glycols