Abstract: The present invention provides a method for determining binding of a receptor to one or more ligands. The method consists of contacting a collective receptor variant population with one or more ligands and detecting binding of one or more ligands to the collective receptor variant population. The collective receptor variant population can be further divided into two or more subpopulations, one or more of the two or more subpopulations can be contacted with one or more ligands and one or more receptor variant subpopulations having binding activity to one or more ligands can be detected. The steps of dividing, contacting and detecting can be repeated one or more times. The invention also provides methods for identifying a receptor variant having optimal binding activity to one or more ligands. The invention additionally provides a method for determining binding of a ligand to one or more receptors.

Abstract: A system and method of mixing and injecting discrete sample mixtures into a flow cytometer or other sample analysis apparatus may generally comprise a sample injection guide coupling a liquid handling apparatus with a sample analysis apparatus and facilitating injection of discrete sample mixtures into a fluidic system of the apparatus.

Abstract: A system and method of mixing and injecting discrete sample mixtures into a flow cytometer or other sample analysis apparatus may generally comprise a sample injection guide coupling a liquid handling apparatus with a sample analysis apparatus and facilitating injection of discrete sample mixtures into a fluidic system of the apparatus.

Abstract: The invention provides a gene targeting construct containing a transgene encoding a polypeptide that contains a rod outer segment (ROS) targeting signal. The transgene is flanked by 5′ and 3′ DNA sequences that are homologous to the rhodopsin gene. Homologous recombination between the construct and a rhodopsin gene results in operable association between the transgene and a rod-specific regulatory sequence. The invention also provides cells and animals whose genome contain a functional disruption of one or both endogenous rhodopsin gene alleles, and a transgene encoding a polypeptide that contains a ROS targeting signal operably associated with a rod-specific regulatory sequence. The invention constructs, cell and animals can be used to isolate transgenic polypeptides from the ROS membrane.