Enhanced recovery of chlorophyll and carotenoids with dextran-polyacrylamide gel electrophoresis

Polyacrylamide gel electrophoresis (PAGE) is a widely used method for separating and analyzing chlorophyll/carotenoid binding-proteins. However, extraction of pigments from the proteins in the gel using organic solvents is inefficient. We modified the gel composition by adding various hydrophilic water-soluble polymers to the acrylamide before polymerization. The inclusion of 3% dextran T500 produced a gel with much more elasticity and greatly improved both the speed and efficiency of pigment extraction. In 30 min, extraction of pigments was completed whether in 80% acetone or in 95% N,N-dimethylformamide. More than 90% of the chlorophyll and carotenoid applied to the ge was recovered by solvent extraction. The current method is advantageous for separation and quantitative analysis of pigments associated with proteins.