Microspheres for the Separation and Refolding of Proteins with an Emphasis on Particles Made of Agarose

The first attempts to use microspheres, in a wider sense of the term, for protein separation were based on batch adsorption to a variety of inorganic materials. The most frequently used were alumina hydrates (Al2O3·nH2O), such as Bauxite, Al-silicates (bentonites), Mgsilicates (soapstone etc.), silicas (SiO2·nH2O), Ca-and Zn-carbonates, Ca-phosphate, iron oxides (hematite, Fe2O3), and Al,Mg-silicate (Florisil). Sometimes, these adsorbents were mixed with filter aids and packed in columns and were used in chromatography. An early review of these techniques was published by Turba in 1954 (1).