We have developed a method for the rapid, quantitative elution of fibrinogen adsorbed alone from aqueous solution to unmodified and to lecithin-coated polystyrene-divinylbenzene beads. More than 98% of adsorbed fibrinogen is eluted from these beads by a single exposure to an aqueous solution containing 4% (w/v) sodium dodecyl sulfate and 5% (v/v) 2-mercaptoethanol. The efficiency of elution is maintained even if beads have been exposed for 24 h at 37°C to solutions containing fibrinogen. In addition to fibrinogen, other proteins that adsorb from plasma to these beads are rapidly and efficiently removed using this formulation. Thus, the SDS 2-ME reagent, in conjunction with the bead system, can be used effectively to identify and quantitate proteins and regions of proteins that adsorb to surfaces in contact with blood, and to probe the role of surfaces in the biologic processing of these proteins. © 1992.