Then, chaotropic agents such as potassium or sodium thiocyanate (KSCN or NaSCN) or urea, can be used to formulate different forms of surface antigen protein aggregates followed by adsorption onto fused silica, borate N-morpholine propanesulfonic acid (MOPS) buffer elution, hydrophobic interaction chromatography on butyl agarose, treatment with polystyrene beads cross-linked with divinylbenzene (Am