title: Quantitation of locked nucleic acid antisense oligonucleotides in mouse tissue using a liquid-liquid extraction LC-MS/MS analytical approach.
abstract: BACKGROUND
  A significant challenge of oligonucleotide bioanalysis is the selective extraction from complex tissue samples, where the molecules that distribute into the intracellular space are extensively protein bound and sit amongst a high concentration of endogenous nucleic acid material. Published analytical methodology currently purports extensive sample preparation requirements that include cell lysis steps, homogenization and dual cleanup with liquid-liquid extraction and solid-phase extraction, prior to injection.
  
  
  RESULTS
  We have developed a simple liquid-liquid extraction approach to rapidly isolate antisense oligonucleotides from biological tissues with high recovery and combined these preparative steps with a robust monolithic column LC-MS/MS setup. The platform showed improved chromatographic resolution and detection sensitivity over standard reversed-phase columns and required a low sample volume.
  
  
  CONCLUSIONS
  The high-throughput method was sufficient to accurately quantify multiple antisense oligonucleotides in mouse tissue and plasma down to low ng/g and ng/ml levels, respectively, for pharmacokinetic determination, and exhibited a high degree of specificity.
authors: Pharmacokinetics, Dynamics & Metabolism Department, Pfizer Global Research & Development, Sandwich, UK. paul.turnpenny@pfizer.com
authors: Paul
authors: P
authors: Turnpenny
authors: Jaiessh
authors: J
authors: Rawal
authors: Torsten
authors: T
authors: Schardt
authors: Sandro
authors: S
authors: Lamoratta
authors: Heiko
authors: H
authors: Mueller
authors: Markus
authors: M
authors: Weber
authors: Kevin
authors: K
authors: Brady
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid / Q000295:instrumentation / Q000379:methods*; D007668:Kidney / Q000737:chemistry; D008099:Liver / Q000737:chemistry; D051379:Mice; D016376:Oligonucleotides, Antisense / Q000032:analysis* / Q000493:pharmacokinetics; D012015:Reference Standards; D052616:Solid Phase Extraction / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000295:instrumentation / Q000379:methods*
chemical_list: D016376:Oligonucleotides, Antisense