A novel procedure for the extraction of protein deposits from soft hydrophilic contact lenses for analysis

Abstract

PURPOSE. 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 ~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.