EPFLの研究者が極低温顕微鏡の新しい地平を切り開く(EPFL scientists unlock new horizons for cryogenic microscopy)

2023-06-08

2023-06-07 スイス連邦工科大学ローザンヌ校(EPFL)

◆スイスの研究グループがCryoNanoSIMS機を開発し、ナノスケール二次イオン質量分析法を向上させました。この装置は、凍結組織サンプルの化学組成を分析することができます。新しい試料準備プロセスにより、生物組織の状態を損なわずに詳細な画像が得られます。
◆この装置は、細胞内の栄養素や薬物の分布を可視化し、植物成長や環境汚染の追跡にも応用できます。また、珊瑚の研究にも使用され、共生メカニズムや白化現象の要因の解明に役立ちます。

＜関連情報＞

生体組織のクライオSEMとCryoNanoSIMSの相関イメージング Correlated cryo-SEM and CryoNanoSIMS imaging of biological tissue

Anders Meibom,Florent Plane,Tian Cheng,Gilles Grandjean,Olivier Haldimann,Stephane Escrig,Louise Jensen,Jean Daraspe,Antonio Mucciolo,Damien De Bellis,Nils Rädecker,Cristina Martin-Olmos,Christel Genoud & Arnaud Comment
BMC Biology Published:07 June 2023
DOI:https://doi.org/10.1186/s12915-023-01623-0

Abstract

Background
The development of nanoscale secondary ion mass spectrometry (NanoSIMS) has revolutionized the study of biological tissues by enabling, e.g., the visualization and quantification of metabolic processes at subcellular length scales. However, the associated sample preparation methods all result in some degree of tissue morphology distortion and loss of soluble compounds. To overcome these limitations an entirely cryogenic sample preparation and imaging workflow is required.

Results
Here, we report the development of a CryoNanoSIMS instrument that can perform isotope imaging of both positive and negative secondary ions from flat block-face surfaces of vitrified biological tissues with a mass- and image resolution comparable to that of a conventional NanoSIMS. This capability is illustrated with nitrogen isotope as well as trace element mapping of freshwater hydrozoan Green Hydra tissue following uptake of ¹⁵N-enriched ammonium.

Conclusion
With a cryo-workflow that includes vitrification by high pressure freezing, cryo-planing of the sample surface, and cryo-SEM imaging, the CryoNanoSIMS enables correlative ultrastructure and isotopic or elemental imaging of biological tissues in their most pristine post-mortem state. This opens new horizons in the study of fundamental processes at the tissue- and (sub)cellular level.

Teaser
CryoNanoSIMS: subcellular mapping of chemical and isotopic compositions of biological tissues in their most pristine post-mortem state.