Comparison of binding of Glu-plasminogen (A) and kringles 1 through 3 (B) to immobilized TF apoprotein as observed with an IAsys optical biosensor. Association and dissociation (wash) buffers were as for the binding of Glu-plasminogen with immobilized soluble TF (Fig 1, first part of Fig 2). Both proteins were injected into the sensor cuvette at 500 nmol/L and the association phase was observed. Dissociation was observed in dissociation buffer after 5 quick (5 seconds) rinses of the sensor cuvette with dissociation buffer. In the case of the plasminogen experiment, 20 mmol/L 6-AHA was added to the rinsed cuvette after buffer-induced dissociation.