title: A novel procedure for the extraction of protein deposits from soft hydrophilic contact lenses for analysis.
abstract: OBJECTIVE
  A quick, simple, and efficient extraction technique was developed for the removal of protein from soft hydrophilic contact lenses.
  
  
  METHODS
  An extraction solvent consisting of a 50:50 mix of 0.2% trifluoroacetic acid and acetonitrile was used to remove protein from in vitro laboratory-deposited and human-worn contact lenses. The protein removed was analyzed using HPLC, bicinchoninic acid (BCA) analysis, and SDS-PAGE gel electreophoresis.
  
  
  RESULTS
  Extraction efficiency for lysozyme from laboratory-deposited Group IV lenses was determined to be approximately 100%. Group IV human-worn contact lenses were extracted and analyzed for lysozyme by HPLC and total protein by bicinchoninic acid (BCA) analysis. Groups I, II, III, and IV contact lenses deposited with an artificial tear protein solution and human-worn lenses were extracted and analyzed by SDS-PAGE gel electreophoresis and micro-BCA.
  
  
  CONCLUSIONS
  The ACN/TFA procedure offers a simple, quick, and efficient extraction technique for removal of protein from contact lenses for subsequent analysis.
authors.affiliation: Akon Laboratories Inc., Fort Worth, TX, USA.
authors.forename: D
authors.initials: D
authors.lastname: Keith
authors.forename: B
authors.initials: B
authors.lastname: Hong
authors.forename: M
authors.initials: M
authors.lastname: Christensen
mesh_terms: D000097:Acetonitriles; D002851:Chromatography, High Pressure Liquid; D018639:Contact Lens Solutions; D003263:Contact Lenses, Hydrophilic; D004338:Drug Combinations; D005136:Eye Proteins / Q000302:isolation & purification*; D006801:Humans; D008722:Methods; D009113:Muramidase / Q000302:isolation & purification; D011804:Quinolines; D012997:Solvents; D013499:Surface Properties; D013666:Tears / Q000737:chemistry; D014269:Trifluoroacetic Acid
chemical_list: D000097:Acetonitriles; D018639:Contact Lens Solutions; D004338:Drug Combinations; D005136:Eye Proteins; D011804:Quinolines; D012997:Solvents; C047117:bicinchoninic acid; D014269:Trifluoroacetic Acid; D009113:Muramidase; C032159:acetonitrile