Focused libraries of genetic packages

[Subject] The library which has the diversity of the length and arrangement imitating the diversity found out in a native human antibody is obtained. [Solution means]. [whether the member of the various families of antibody peptide, antibody polypeptide, and the quality of antibody protein is shown, and] It is considered as the library with which the vector or the focus of a hereditary package which presents collectively at least one copy of diversity which showed, and was revealed, contained, and united the focus of this antibody family, or is shown, is revealed, or is included was united. [Selection figure] Nothing