Visualizing heterocyst development in cyanobacteria via live-cell coherent Raman scattering microscopy

Label-free bioimaging is a powerful approach for understanding chemical pathways in live cells under non-perturbative illumination conditions but suffers from limited spatial resolution. Visualizing phenomena such as cell differentiation in photosynthetic organisms has the additional challenge that chlorophyll autofluorescence may obscure chemical information. Here, we use label-free stimulated Raman scattering (SRS) microscopy for tracking the development of heterocysts in live cyanobacteria. These results highlight the need for chemically sensitive optical tools able to resolve the spatial dimensions of subcellular features and cellular junctions. We also describe our progress developing structured illumination coherent microscopy which addresses this challenge.