Developments in biological assays by a noncompetitive detection of peptides

利用抗体可变（Fv）区抗原依赖性稳定化的免疫分析法（Open-sandwich immunoassay, OS-IA），我们试图创建一种非竞争性敏感检测小分子肽的系统，这是传统三明治法无法测量的。绕过杂交瘤，利用新开发的抗体Fab片段噬菌体展示系统，以甲状腺素和高致病性流感病毒抗原肽为抗原，直接从偶联免疫小鼠中获得了抗OS-IA的良好抗体。此外，基于OS-IA原理，利用非偶联小分子抗原进行亲和成熟的OS-selection方法可将骨钙素肽的敏感性提高数百倍。

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.