title: Fourier transform infrared spectroscopy imaging of live epithelial cancer cells under non-aqueous media.
abstract: OBJECTIVE
  Fourier transform infrared (FT-IR) imaging is increasingly being applied to biomedical specimens, but strong IR absorption by water complicates live cell imaging. This study investigates the viability of adherent epithelial cells maintained for short periods under mineral oils in order to facilitate live cell spectroscopy using FT-IR with subsequent imaging.
  
  
  METHODS
  The MGH-U1 urothelial or CaCo2 colorectal cancer cell lines were grown on plastic surfaces or mid-range infrared transparent windows. Medium in established cultures was replaced with paraffin mineral oil, or Fluorolube, for up to 2 h, and viability assessed by supravital staining. Drug handling characteristics were also assessed. Imaging of preparations was attempted by reflectance and transmission using a Varian FT-IR microscope.
  
  
  RESULTS
  Cells covered by mineral oil remained viable for 2 h, with recovery into normal medium possible. MTT ((3-(4,5-dimethylthlazol-2-yl)-2,5-diphenyl tetrazolium) conversion to crystalline formazan and differential patterns of drug uptake were maintained. The combination of a calcium fluoride substrate, Fluorolube oil, and transmission optics proved best for spectroscopy. Spectral features were used to obtain images of live cells.
  
  
  CONCLUSIONS
  The viability of cells overlaid with IR transparent oils was assessed as part of a technique to optimise conditions for FT-IR imaging. Images of untreated cells were obtained using both reflectance and transmission. This represents an effective means of imaging live cells by IR spectroscopy, and also means that imaging is not necessarily a terminal event. It also increases options for producing images based on real-time biochemistry in a range of in vitro experimental and 'optical biopsy' contexts.
authors: School of Pharmacy and Biomedical Sciences, Portsmouth University, Portsmouth, Hampshire, UK.
authors: JunYi
authors: J
authors: Soh
authors: Adeline
authors: A
authors: Chueng
authors: Aminat
authors: A
authors: Adio
authors: Alan J
authors: AJ
authors: Cooper
authors: Brian R
authors: BR
authors: Birch
authors: Bashir A
authors: BA
authors: Lwaleed
mesh_terms: D018938:Caco-2 Cells; D002124:Calcium Fluoride / Q000737:chemistry; D002448:Cell Adhesion; D002470:Cell Survival; D015251:Epirubicin / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology*; D004867:Equipment Design; D006801:Humans; D008899:Mineral Oil / Q000737:chemistry*; D009375:Neoplasms, Glandular and Epithelial / Q000378:metabolism / Q000473:pathology*; D009821:Oils / Q000737:chemistry*; D010232:Paraffin / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared / Q000295:instrumentation; D013778:Tetrazolium Salts / Q000378:metabolism; D013844:Thiazoles / Q000378:metabolism; D013997:Time Factors
chemical_list: D009821:Oils; D013778:Tetrazolium Salts; D013844:Thiazoles; D015251:Epirubicin; D010232:Paraffin; C015418:paraffin oils; D008899:Mineral Oil; C022616:thiazolyl blue; D002124:Calcium Fluoride