Online laser light scattering coupled with imaging for pressurized capillary gel filtration

A system combining pressurized capillary gel filtration with online laser light scattering and microscopic imaging, particularly suitable for biological applications, has been developed. Structural information of eluted materials in the gel filtration provides important clues about their behavior and how they interact with light. It also reveals that the dispersion of the column packing materials is the major limiting factor in the improvement of detectability. Surprisingly, it is found that eluted lysozymes actually scatter light coherently with two distinctive features: a very strong scattering characteristic of constructive interference and a very weak scattering consistent with destructive interference. A variation of the incident angle by 2 degrees of the laser beam caused a swing between the two features. Albumins and large blue dextran particles scatter light simply as individual particles.