Abstract: Methods of generating modified embryos and mammals by introduction of donor cells into an early stage embryo are provided, such that the resulting embryo and animal generated therefrom has a significant contribution to all tissues from the donor cells and is capable of transmitting the donor cell DNA.

Abstract: The present invention provides a method of achieving very high targeting efficiency by utilizing targeting vectors that utilize promoter-less selection cassettes and which are engineered to targeted into transcriptionally active loci. In particular, the invention provides a method for targeting promoter-less selection cassettes into transcriptionally active loci in stem cells or other eukaryotic cells with much greater efficiency than previously observed with other methods, thus reducing the number of drug-resistant clones to be screened or eliminating the need to screen for targeted cells altogether. The invention also encompasses the DNA targeting vectors, the targeted cells, as well as non-human organisms, especially mice, created from the targeted cells.

Abstract: A method of detecting and isolating cells that produce any secreted protein of interest (POI), comprising: a) constructing a cell line transiently or stably expressing a cell surface capture molecule, which binds the POI, by transfecting the cell line with a nucleic acid that encodes such cell surface capture molecule; b) transfecting said cell simultaneously or subsequently with a second nucleic acid that encodes a POI wherein such POI is secreted; c) detecting the surface-displayed POI by contacting the cells with a detection molecule, which binds the POI; and d) isolating cells based on the detection molecule.