Developments in biological assays by a noncompetitive detection of peptides

使用利用抗体可变（Fv）区的抗原依赖性稳定化的免疫测定（开放夹心免疫测定，OS-IA），我们试图创建用于小分子肽的非竞争性灵敏检测的系统，这是通过常规夹心测定不可测量的。利用新近开发的噬菌体抗体Fab段展示系统，通过杂交瘤的筛选，成功地从以甲状腺素和高致病性流感病毒抗原肽为抗原的结合免疫小鼠中直接获得了抗OS-IA的良好抗体。此外，通过OS选择，这是一种基于OS-IA原理使用未缀合的小分子抗原进行亲和力成熟的方法，我们可以将骨钙素肽的灵敏度提高数百倍。

Using an immunoassay that utilizes the antigen-dependent stabilization of antibody variable (Fv) regions (Open-sandwich immunoassay, OS-IA), we attempted to create systems for non-competitive sensitive detection of small molecular peptides, which was not measurable by conventional sandwich assays. Bypassing hybridoma, by utilizing newly developed phage display system for antibody Fab fragments, we succeeded in directly obtaining good antibodies for OS-IA from conjugate-immunized mice with thyroxine and an antigenic peptide from highly pathogenic influenza virus as antigens. Moreover, by OS-selection which is a method for affinity maturation using unconjugated small molecule antigens based on the OS-IA principle, we could improve the sensitivity for osteocalcin peptide by several hundred fold.