Wavelength-encoded laser particles for massively multiplexed cell tagging


Large-scale single-cell analyses have become increasingly important given the role of cellular heterogeneity in complex biological systems. However, no techniques at present enable optical imaging of uniquely tagged individual cells. Fluorescence-based approaches can distinguish only a small number of distinct cells or cell groups at a time because of spectral crosstalk between conventional fluorophores. Here we investigate large-scale cell tracking using intracellular laser particles as imaging probes that emit coherent laser light with a characteristic wavelength. Made of silica-coated semiconductor microcavities, these laser particles have single-mode emission over a broad range from 1,170 nm to 1,580 nm with sub-nanometre linewidths, enabling massive spectral multiplexing. We explore the stability and biocompatibility of these probes in vitro and their utility for wavelength-multiplexed cell tagging and imaging. We demonstrate real-time tracking of thousands of individual cells in a three-dimensional tumour model over several days, showing different behavioural phenotypes.

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Fig. 1: Optical properties of semiconductor microdisk lasers.
Fig. 2: Highly multiplexed microdisk lasers.
Fig. 3: Silica coating of III−V semiconductor microdisk lasers.
Fig. 4: Stability and biocompatibility of LPs.
Fig. 5: High-speed imaging and characterization of LPs as cell tagging probes.
Fig. 6: Cell tracking in a tumour spheroid.

Data availability

The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request.


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This work was supported by the US National Institutes of Health (NIH) grants DP1-OD022296, P41-EB015903, R01-CA192878, and National Science Foundation (NSF) grants ECCS-1505569. Electron microscopy was performed in the Microscopy Core of the Center for Systems Biology/Program in Membrane Biology, which is partially supported by an Inflammatory Bowel Disease Grant DK043351 and a Boston Area Diabetes and Endocrinology Research Center (BADERC) Award DK057521. This research used the resources of the Center for Functional Nanomaterials, which is a US Department of Energy Office of Science User Facility, at Brookhaven National Laboratory under contract number DE-SC0012704 and of the Center for Nanoscale Systems, part of Harvard University, a member of the National Nanotechnology Coordinated Infrastructure Network (NNCI), which is supported by the NSF under award number 1541959. We thank V. Vinarsky and D. Montoro for their comments, and F. Camino for helping with focused ion beam measurements.

Author information




S.-H.Y., N.M. and S.J.J.K. conceived and designed the project. N.M., H.J., H.-M.K., Y.-H.L. and S.-H.Y. designed microdisks. N.M. and A.C.L. fabricated microdisks. N.M. and S.J.J.K. developed the microdisk transfer protocol. S.J.J.K. and S.J.W. developed and performed silica coating of microdisks. N.M. and A.C.L. conducted theoretical simulations. S.J.J.K., S.F. and S.-J.J. performed cell cultures and biocompatibility assays. N.M. and J.W. designed the LASE microscope system. N.M. and S.J.J.K. performed and analysed optical characterization and imaging of LPs. S.J.J.K. and S.-J.J. performed ex vivo lung imaging. S.J.J.K., A.C.L., S.F., S.-J.J. and P.H.D. analysed time-lapse videos of intracellular LPs. N.M., S.J.J.K., A.C.L. and S.-H.Y. prepared figures and wrote the manuscript with input from all authors.

Corresponding author

Correspondence to Seok-Hyun Yun.

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Competing interests

The authors declare the following competing interests: S.-H.Y. holds patents on technologies related to the devices developed in this work. S.-H.Y. and S.J.J.K. have financial interests in LASE Innovation Inc., a company focused on commercializing technologies based on LPs, for a variety of applications in life science and healthcare. S.-H.Y.’s interests were reviewed and are managed by Massachusetts General Hospital and Partners HealthCare in accordance with their conflict of interest policies.

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Supplementary information

Supplementary Information

Laser particle optical characterization, biocompatibility, tracking algorithm analysis.

Reporting Summary

Supplementary Video 1

Uptake of LPs by MDCK-II cells

Supplementary Video 2

Time-lapse brightfield imaging of intracellular LPs

Supplementary Video 3

Time-lapse brightfield imaging of intracellular LPs

Supplementary Video 4

Time-lapse brightfield imaging of intracellular LPs

Supplementary Video 5

Time-lapse imaging of tumour spheroid

Supplementary Video 6

Time-lapse imaging of cell movement in tumour spheroid

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Martino, N., Kwok, S.J.J., Liapis, A.C. et al. Wavelength-encoded laser particles for massively multiplexed cell tagging. Nat. Photonics 13, 720–727 (2019). https://doi.org/10.1038/s41566-019-0489-0

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