増幅不要CRISPRによる核酸の相対定量法を実現(Amplification-free CRISPR Enables Relative Quantification of Nucleic Acids)

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2026-07-03 中国科学院(CAS)

中国科学院合肥物質科学研究院のZHU Ling教授らは、核酸増幅を行わずに微量核酸を相対定量できるデジタルCRISPR検出システム「CrisprDEM(Digital CRISPR Hydrogel Fluorescence-Enhancing Microsphere Sensing System)」を開発した。従来のCRISPR/Cas12aを用いた増幅不要型核酸検出法は、高い特異性を持つ一方で、感度や定量性に課題があり、感染症の早期診断やがんリキッドバイオプシーへの応用が制限されていた。本研究では、ハイドロゲル微小ビーズを反応場として利用し、CRISPR/Cas12aの副次的切断反応で生じる蛍光シグナルを空間的に濃縮することで、検出感度を大幅に向上させた。さらに、マイクロ流体チップによりビーズを単層配置して安定した画像取得を実現し、教師なし機械学習であるK-meansクラスタリングを用いて陽性・陰性ビーズを自動分類した。加えて、「Positive Bead Ratio」という新たな指標を導入し、核酸の事前増幅なしで標的核酸量を相対定量する手法を確立した。本技術は、低濃度病原体の迅速検出やポイントオブケア診断、感染症の早期スクリーニングなどへの応用が期待される。

<関連情報>

CRISPR/Cas12aを用いたデジタルハイドロゲル蛍光増強マイクロビーズによる核酸の増幅不要相対定量 Digital Hydrogel Fluorescent-Enhancing Microspheres via CRISPR/Cas12a for Amplification-Free Relative Quantification of Nucleic Acids

Xueer Yin,Qiangyuan Xiong,Taowei Shu,Sichen Yan,Jun Zhao,Zhenyu Wang,Guoqing Deng,Yong Liu,Ling Zhu,and Cancan Zhu
Analytical Chemistry  Published: June 8, 2026
DOI:https://doi.org/10.1021/acs.analchem.6c01288

Abstract

増幅不要CRISPRによる核酸の相対定量法を実現(Amplification-free CRISPR Enables Relative Quantification of Nucleic Acids)

CRISPR/Cas systems hold great promise for molecular diagnostics, but their amplification-free applications are hampered by weak signals and poor quantification. Here, we developed CrisprDEM, a CRISPR/Cas12a-based digital hydrogel fluorescent-enhancing microsphere system that integrates hydrogel microsphere confinement, microfluidic digital imaging, and machine learning for ultrasensitive and quantitative nucleic acid detection without amplification. Hydrogel microspheres (HMs) efficiently captured and spatially concentrated CRISPR/Cas12a reaction reporters, achieving a 1000-fold signal amplification compared with homogeneous methods. The design of the microfluidic chip arranged the microspheres into a single-layer array, making each microsphere an independent digital reporting unit. The Intelligent Bead Analysis Software enabled automatic analysis and relative quantification via a positive bead ratio (PBR). As a proof-of-concept, we selected the respiratory adenovirus as the detection target. We optimized the CRISPR/Cas12a-microsphere enrichment reaction system and characterized the morphologies and chemical properties of the microspheres before and after enrichment. The results demonstrated that CrisprDEM technology exhibited a detection sensitivity of 10 aM for respiratory adenovirus, exhibiting no cross-reactivity with other respiratory viruses, indicating a high specificity. In the validation of 20 clinical samples, the detection results were consistent with the gold-standard real-time quantitative polymerase chain reaction (qPCR), and the PBR value showed a good linear relationship with the cycle threshold (Ct) value, enabling a relative quantification. This system expands the toolbox for amplification-free CRISPR diagnostics and holds the potential for point-of-care and early infection detection.

細胞遺伝子工学
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