Food Research Center, Central Laboratory, Nippon Flour Mills Co., Ltd., 5-1-3 Midorigaoka, Atsugi, Kanagawa, 243-0031, Japan.
Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259-R1-18 Nagatsuta-cho, Midori, Yokohama, Kanagawa, 226-8503, Japan.
Anal Sci. 2021 Mar 10;37(3):455-459. doi: 10.2116/analsci.20SCP06. Epub 2020 Nov 20.
Immunochromatography assay is an easy and rapid on-site detection method. However, conventional sandwich immunochromatographies using two antibodies can only detect target molecules above a threshold size. Small molecules below 1000 in molecular weight are usually detected using competitive immunoassay. However, competitive immunoassay is not suitable for visual detection of low concentration samples. Based on the principles of open sandwich immunoassay, which detects small molecules via interchain interaction of separated variable region fragments (V and V) from a single antibody, we developed non-competitive open sandwich immunochromatography. Bone Gla protein (BGP)-C7, a peptide containing the seven C-terminal amino acids of human osteocalcin, was selected as the target. By using V fragments fixed on a nitrocellulose membrane, and colored cellulose bead-labeled V fragments, we specifically detected 10 ng/mL of BGP-C7. This is the first report of open sandwich immunochromatography, which is an easy and rapid method for on-site, signal-on detection of small molecules.
免疫层析法是一种简单、快速的现场检测方法。然而，传统的使用两种抗体的夹心免疫层析法只能检测大小超过阈值的目标分子。分子量在 1000 以下的小分子通常使用竞争免疫分析法进行检测。然而，竞争免疫分析法不适合用于低浓度样品的可视化检测。基于开放式夹心免疫分析法的原理，该方法通过从单克隆抗体中分离的可变区片段 (V 和 V) 的链间相互作用来检测小分子，我们开发了非竞争性开放式夹心免疫层析法。骨钙素 C 端肽 7 （BGP-C7），一种含有 7 个人体骨钙素 C 端氨基酸的肽，被选为靶标。通过使用固定在硝酸纤维素膜上的 V 片段和带有颜色的纤维素珠标记的 V 片段，我们可以特异性地检测到 10ng/mL 的 BGP-C7。这是开放式夹心免疫层析法的首次报道，它是一种简单、快速的现场、信号开启小分子检测方法。
