Coherent Raman imaging – 3D quantitative chemical analysis of cells and tissues

Wolfgang Langbein
School of Physics & Astronomy, Cardiff University, CF24 3AA Cardiff, United Kingdom, langbeinww@cf.ac.uk

Optical microscopy is an indispensable tool that is driving progress in cell biology, and is still the only practical means of obtaining spatial and temporal resolution within living cells and tissues. Coherent Raman Scattering (CRS) microscopy has attracted increasing attention as a powerful multiphoton microscopy technique which overcomes the need of fluorescent labelling and yet retains biomolecular specificity and intrinsic 3D resolution [1]. Over the past 10 years, our laboratory has developed and demonstrated a range of label-free CRS microscope set-ups featuring innovative excitation/detection schemes and quantitative image analysis. Using hyperspectral imaging [2] and associated quantitative chemical imaging algorithms and unsupervised analysis [3], we have determined the lipid uptake of fixed and living adipose derived human stem cells differentiating into pre-adipocytes [4], the lipid content and spatial distribution in live mammalian oocytes and early embryos [5], addressed drug-induced lipid storage within hepatic tissue [6], and quantitatively measured masses of lipids, proteins and DNA during cell division [7]. We have also shown that CARS can be used to visualise single non-fluorescing nanodiamonds in cells [8] and developed [9] epi-detected heterodyne CARS (eH-CARS) imaging of individual lipid bilayers. I will present our latest progress with these techniques and their applications to bio-imaging.

[1] A. Zumbusch, W. Langbein, P. Borri, Progress in Lipid Research 52, 615 (2013).
[2] I. Pope et al, Optics Express 21, 7096 (2013).
[3] Francesco Masia et al, Anal. Chem. 85, 10820 (2013).
[4] C. Di Napoli et al., Anal. Chem. 88, 3677-3685 (2016).
[5] J. Bradely et al., Development 143, 2238 (2016).
[6] F. Masia et al., Anal. Chem. 90, 3775 (2018).
[7] A. Karuna et al., Anal. Chem. 91, 2813 (2019).
[8] I. Pope et al., Nat. Nanotechnol. 9, 940 (2014).
[9] W. Langbein et al., APL Photonics 3, 092402 (2018)