Identification of intracellular squalene in living algae, Aurantiochytrium mangrovei with hyper-spectral coherent anti-Stokes Raman microscopy using a sub-nanosecond supercontinuum laser source

We applied hyper-spectral coherent anti-Stokes Raman scattering imaging to intracellular lipid identification in living microalgae, Aurantiochytrium mangrovei 18W-13a. Two different lipids, squalene and triacylglycerol, were found inside living cells with clear vibrational contrast. Based on the endogenous lipid band as a result of the cis C[DOUBLE BOND]C stretch vibrational mode, squalene and triacylglycerol were clearly distinguished in different intracellular areas. In particular, squalene was detected solely in vacuoles as lipid particles, which was also supported by electron microscopy.