Label-free 3D computational imaging of spermatozoon locomotion, head spin and flagellum beating over a large volume

Mustafa Ugur Daloglu; Wei Luo; Faizan Shabbir; Francis Lin; Kevin Kim; Inje Lee; Jia-Qi Jiang; Wen-Jun Cai; Vishwajith Ramesh; Meng-Yuan Yu; Aydogan Ozcan

doi:10.1038/lsa.2017.121

Label-free 3D computational imaging of spermatozoon locomotion, head spin and flagellum beating over a large volume

Light Sci Appl. 2018 Jan 12:7:17121. doi: 10.1038/lsa.2017.121. eCollection 2018.

Authors

Mustafa Ugur Daloglu^{1

2

3}, Wei Luo^{1

2

3}, Faizan Shabbir¹, Francis Lin², Kevin Kim⁴, Inje Lee², Jia-Qi Jiang⁵, Wen-Jun Cai⁶, Vishwajith Ramesh², Meng-Yuan Yu⁷, Aydogan Ozcan^{1

2

3

8}

Affiliations

¹ Electrical and Computer Engineering Department, University of California, Los Angeles, CA 90095, USA.
² Bioengineering Department, University of California, Los Angeles, CA 90095, USA.
³ California NanoSystems Institute (CNSI), University of California, Los Angeles, CA 90095, USA.
⁴ Chemistry and Biochemistry Department, University of California, Los Angeles, CA 90095, USA.
⁵ Department of Physics and Astronomy, University of California, Los Angeles, CA 90095, USA.
⁶ Department of Mathematics, University of California, Los Angeles, CA 90095, USA.
⁷ Computer Science Department, University of California, Los Angeles, CA 90095, USA.
⁸ Department of Surgery, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA.

Abstract

We report a high-throughput and label-free computational imaging technique that simultaneously measures in three-dimensional (3D) space the locomotion and angular spin of the freely moving heads of microswimmers and the beating patterns of their flagella over a sample volume more than two orders-of-magnitude larger compared to existing optical modalities. Using this platform, we quantified the 3D locomotion of 2133 bovine sperms and determined the spin axis and the angular velocity of the sperm head, providing the perspective of an observer seated at the moving and spinning sperm head. In this constantly transforming perspective, flagellum-beating patterns are decoupled from both the 3D translation and spin of the head, which provides the opportunity to truly investigate the 3D spatio-temporal kinematics of the flagellum. In addition to providing unprecedented information on the 3D locomotion of microswimmers, this computational imaging technique could also be instrumental for micro-robotics and sensing research, enabling the high-throughput quantification of the impact of various stimuli and chemicals on the 3D swimming patterns of sperms, motile bacteria and other micro-organisms, generating new insights into taxis behaviors and the underlying biophysics.

Keywords: flagellar motion; holography; on-chip microscopy; sperm head spin; sperm tracking.