pFUSE-CHIg-ratG1 pFUSE-CHIg-ratG1 is a cloning plasmid that expresses the constant region of the rat IgG1 heavy chain. It contains a multiple cloning site upstream of the constant region to enable cloning of the heavy chain variable region. This plasmid is designed for antibody generation when co-transfected into mammalian cells with the light chain variable region cloned into pFUSE-CLIg. pFUSEss-CHIg-ratG1 additionally features the IL2 signal sequence to allow the secretion of recombinant antibodies generated using fragment antigen-binding (Fab) or single-chain variable fragment (scFv) fragments selected from phage display libraries that lack a signal sequence. • pFUSE-CHIg-ratG1 features the constant region of the rat IgG1 heavy chain • pFUSEss-CHIg-ratG1 features the constant region of the rat IgG1 heavy chain and the IL2 signal sequence Both plasmids are selectable with Zeocin™.