Abstract: The invention relates to devices for continuously measuring the concentrations of more than one target analyte. Specifically, the devices comprise a plurality of analyte binding domains, with each domain being capable of specifically and reversibly binding to at least one of the target analytes. The devices further comprise a membrane surrounding these binding domains that is permeable to the target analytes. The devices convey binding information to a detector. The invention also relates to methods of using the devices, including monitoring chronic disease states in an individual.

Abstract: The present invention relates to methods of screening or isolating stable mutant binding proteins from a protein library of mutant proteins. The methods comprise culturing host cells under conditions suitable for protein expression. The collection of host cells comprise collectively a set of expression vectors, and this collection of expression vectors encodes the various members of a protein library of mutant binding proteins. The cultured cells, harboring the expression vectors, are contacted with a ligand, and differences in interaction, among the individual host cells, with the ligand are detected. The individual host cells displaying the desired interaction with the ligand are then separated from individual host cells that do not display the desired interaction with the ligand.