title: A method for continuous and stable perfusion of tissue and single cell preparations with accurate concentrations of volatile anaesthetics.
abstract: BACKGROUND
  It is difficult to design a system to reliably deliver volatile anaesthetics such as halothane or isoflurane to in vitro preparations such as tissues or cells cultures: the very volatility of the drugs means that they can rapidly dissipate from even carefully-prepared solutions. Furthermore, many experiments require the control of other gases (such as oxygen or carbon dioxide) which requires constant perfusion.
  
  
  METHODS
  We describe a constant perfusion system that is air-tight (i.e., allows the accurate administration of hypoxic or hypercapnic gas mixtures), in which volatile anaesthetic is delivered via calibrated vaporisers by constant bubbling into the perfusing solution (and continuously monitored for stability by infrared spectroscopy in the headspace above the solution).
  
  
  RESULTS
  We have confirmed the accuracy (i.e., linear relationship of dissolved concentrations with vapour dial settings) and stability (i.e., over time) of the anaesthetic concentrations in solutions in samples taken from the bottles into which anaesthetic is bubbled, and from samples taken from the tissue perfusion bath, using gas chromatrography-mass spectrometry (GC-MS).
  
  
  CONCLUSIONS
  It is possible to deliver volatile anaesthetics in accurate concentrations to cell/tissue preparations whilst adjusting ambient air composition rapidly, stable over sustained time periods.
authors.affiliation: Department of Physiology, Anatomy & Genetics, University of Oxford, Parks Road, Oxford OX1 3PT, UK.
authors.forename: Nicky
authors.initials: N
authors.lastname: Huskens
authors.affiliation: Department of Physiology, Anatomy & Genetics, University of Oxford, Parks Road, Oxford OX1 3PT, UK; Nuffield Department of Anaesthetics, Oxford University Hospitals NHS Trust, Oxford OX3 9DU, UK.
authors.forename: Peadar
authors.initials: P
authors.lastname: O'Donohoe
authors.affiliation: Mass Spectrometry Research Facility Chemistry Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK.
authors.forename: James R
authors.initials: JR
authors.lastname: Wickens
authors.affiliation: Mass Spectrometry Research Facility Chemistry Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK.
authors.forename: James S O
authors.initials: JS
authors.lastname: McCullagh
authors.affiliation: Department of Physiology, Anatomy & Genetics, University of Oxford, Parks Road, Oxford OX1 3PT, UK.
authors.forename: Keith J
authors.initials: KJ
authors.lastname: Buckler
authors.affiliation: Nuffield Department of Anaesthetics, Oxford University Hospitals NHS Trust, Oxford OX3 9DU, UK. Electronic address: jaideep.pandit@dpag.ox.ac.uk.
authors.forename: Jaideep J
authors.initials: JJ
authors.lastname: Pandit
mesh_terms: D018685:Anesthetics, Inhalation / Q000008:administration & dosage*; D010477:Perfusion / Q000295:instrumentation / Q000379:methods*
chemical_list: D018685:Anesthetics, Inhalation
keywords: Gas chromatography–mass spectrometry; Infrared analyses; Perfusion rig; Volatile anaesthetics