A microfluidic approach for the directed evolution of proteins by retroviral display
The model system used here is based on retroviral particles displaying tPA, a protein used in current emergency therapies of myocardial infarction and stroke. Single tPA variants were encapsulated into aqueous droplets, at a frequency of ~10Kilohertz and the enzymatic activity was monitored using a fluorescence assay. Active variants could be clearly distinguished from inactive variants or variants incubated with the endogenous inhibitor PAI-1.
