Blue dextran is used in affinity chromatography allowing for the identification of proteins, (purified or in crude cellular extracts), and improving the purification procedures for various proteins (1). Bearing Cibacron Blue F3G-A, blue dextran was very early found to bind to pyruvate kinase1, and this observation enabled the purification of a whole series of proteins and essentially brought the use of textile dyes in protein purification to the fore (2). Blue dextrans are also utilized in gel filtration chromatography, protein chromatography as well as molecular weight markers.
1. Thompson, S. T., Cass, K. H. & Stellwagen, E. Blue dextran-sepharose: an affinity column for the dinucleotide fold in proteins. PNAS 72, 669–672 (1975).
2. Wilson, I. D., Adlard, E. R., Cooke, M. & Poole, C. F. Encyclopedia of Separation Science. (Academic Press, 2000).