Blue Dextran is widely used in biochemical and molecular biology research as a marker or tracer. Its primary application is in gel filtration chromatography, where it serves as a high-molecular-weight marker to determine the void volume of a column. This helps in calibrating the column and understanding the separation characteristics of other molecules based on their size. Additionally, it is utilized in studies involving membrane permeability and blood-brain barrier research due to its large size and visibility. Its blue color makes it easy to track visually or spectrophotometrically, aiding in experimental setups and analyses.