Multifocal imaging for precise, label-free tracking of fast biological processes in 3D

Hansen, J. N., Gong, A., Wachten, D., Pascal, R., Turpin, A. , Jikeli, J. F., Kaupp, U. B. and Alvarez, L. (2021) Multifocal imaging for precise, label-free tracking of fast biological processes in 3D. Nature Communications, 12, 4574. (doi: 10.1038/s41467-021-24768-4) (PMID:34321468) (PMCID:PMC8319204)

Abstract

Many biological processes happen on a nano- to millimeter scale and within milliseconds. Established methods such as confocal microscopy are suitable for precise 3D recordings but lack the temporal or spatial resolution to resolve fast 3D processes and require labeled samples. Multifocal imaging (MFI) allows high-speed 3D imaging but is limited by the compromise between high spatial resolution and large field-of-view (FOV), and the requirement for bright fluorescent labels. Here, we provide an open-source 3D reconstruction algorithm for multi-focal images that allows using MFI for fast, precise, label-free tracking spherical and filamentous structures in a large FOV and across a high depth. We characterize fluid flow and flagellar beating of human and sea urchin sperm with a z-precision of 0.15 µm, in a volume of 240 × 260 × 21 µm, and at high speed (500 Hz). The sampling volume allowed to follow sperm trajectories while simultaneously recording their flagellar beat. Our MFI concept is cost-effective, can be easily implemented, and does not rely on object labeling, which renders it broadly applicable.

• Item Type: Articles
• Additional Information: This work was funded by the German Research Foundation (DFG) under Germany’s Excellence Strategy—EXC2151—project number 390873048 (D.W.), SPP1726 “Microswimmers” (L.A., U.B.K., J.F.J., and D.W.), as well as the Boehringer Ingelheim Fonds (J.N.H.) and the Alexander von Humboldt Foundation (A.T.).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Turpin, Dr Alejandro
• Authors: Hansen, J. N., Gong, A., Wachten, D., Pascal, R., Turpin, A., Jikeli, J. F., Kaupp, U. B., and Alvarez, L.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Nature Communications
• Publisher: Nature Research
• ISSN: 2041-1723
• ISSN (Online): 2041-1723
• Copyright Holders: Copyright © The Author(s) 2021
• First Published: First published in Nature Communications 12(1):4574
• Publisher Policy: Reproduced under a Creative Commons Licence