細胞内の構造と微粒子の動きを同時観察する顕微鏡を開発～前後方向の散乱光を同時にとらえる“双方向定量散乱顕微鏡”～

2025-11-14 東京大学

図1:双方向定量散乱顕微鏡の原理
a 散乱体の大きさに対する前方散乱光および後方散乱光の強度と、それぞれの検出可能範囲。b双方向定量散乱顕微鏡の光学系概略図。c 1枚の計測画像から前方・後方散乱画像を再構成する空間周波数多重化の解析例。周波数空間上で分離された成分を個別に解析することで、前方散乱光および後方散乱光の定量画像を算出できる。

<関連情報>

• https://www.s.u-tokyo.ac.jp/ja/press/10974/
• https://www.nature.com/articles/s41467-025-65570-w

双方向定量散乱顕微鏡 Bidirectional quantitative scattering microscopy

Kohki Horie,Keiichiro Toda,Takuma Nakamura & Takuro Ideguchi
Nature Communications  Published:14 November 2025
DOI:https://doi.org/10.1038/s41467-025-65570-w

Abstract

Quantitative phase microscopy (QPM) and interferometric scattering (iSCAT) microscopy are powerful label-free imaging techniques that are widely used in biomedical applications. Each method, however, possesses distinct limitations: QPM, which measures forward scattering (FS), excels at imaging microscale structures but struggles with rapidly moving nanoscale objects, whereas iSCAT, based on backward scattering (BS), is highly sensitive to nanoscale dynamics but lacks the ability to comprehensively image microscale structures. Here, we introduce bidirectional quantitative scattering microscopy (BiQSM), an approach that integrates FS and BS detection using off-axis digital holography with bidirectional illumination and spatial-frequency multiplexing. BiQSM achieves spatiotemporal consistency and a dynamic range 14 times wider than QPM, enabling simultaneous imaging of nanoscale and microscale cellular components. We demonstrate BiQSM’s ability to reveal spatiotemporal behaviors of intracellular structures and small particles using FS and BS images. Time-lapse imaging of dying cells further highlights BiQSM’s potential as a label-free tool for monitoring cellular vital states through structural and motion-related changes. By bridging the strengths of QPM and iSCAT, BiQSM advances quantitative cellular imaging, opening avenues for studying dynamic biological processes.