<p> An experimental method for monitoring the adsorption of proteins in real time has been developed and is the topic of this thesis.</p> <p> Proteins were radioactively labeled using 125I and injected at a constant flow rate into a well stirred glass cell containing buffer and the adsorbing surface in particle form. The buffer contained in the cell was gradually displaced by the protein solution. NaI(TI) detectors, coupled to a multichannel analyzer and high voltage power supply, were placed at the exit of the cell to monitor the radioactivity of the bulk solution. Adsorption of the protein was determined by depletion of protein in the bulk solution.</p> <p> A process to treat the surface of the cell and the glass tubing so as to prevent adsorption was developed and implemented prior to the flow experiments. This procedure involved exposing the cell and glass tubing to a 1 mg/mL fibrinogen solution for two hours at room temperature. The cell and tubing were then placed in an oven for 10 minutes at 70° C. This procedure (referred to as the thermal treatment procedure) resulted in a non-adsorbing protein layer that appeared, from extensive experiments, to be irreversibly attached to the surface of the cell and tubing.</p> <p> The adsorption of fibrinogen from a single component system, as well as from plasma, was studied using the experimental arrangement described above. Concentrations of fibrinogen in isotonic Tris, for the single component system, ranged from 40 mg/mL to 300 mg/mL. It was found from these experiments that an initial, fairly rapid, adsorption of protein took place. Later the adsorption of protein slowed significantly.</p> <p> The adsorption and subsequent desorption of fibrinogen from diluted plasma was also studied. Dilutions ranged from 1% to 20%. The results from these experiments are consistent with the model proposed by Vroman for plasma surface interactions.</p> / Thesis / Master of Engineering (MEngr)