Herein are reported the cell lines DSM ACC3006, DSM ACC3007, and DSM ACC3008, as well as the antibodies obtained from the cell lines and the use of an antibody obtained from the cell lines in an immunoassay. Also are reported antibodies binding to human or chimpanzee IgG and not binding to canine and marmoset IgG and antibodies specifically binding to an IgG 1 that comprises a kappa light chain constant domain.