Label‐free detection of polysulfides and glycogen of <scp><i>Cyanidium caldarium</i></scp> using ultra‐multiplex coherent anti‐Stokes Raman scattering microspectroscopy

Abstract

Abstract Living microalga Cyanidium caldarium was visualized using ultra‐multiplex coherent anti‐Stokes Raman scattering (CARS) microspectroscopy. The Raman band related to the SO 4 2− ion at 982 cm −1 was detected at the peripheral part of the cells and showed a signal amplitude that was approximately threefold larger than that in the medium, indicating accumulation of SO 4 2− ions. Depending on the incubation conditions, a broad and sharp Raman band at approximately 505 cm −1 was observed at the peripheral part and inside the cells, respectively. Based on comparison of the results with model substances, these broad and sharp bands were assigned to polysulfides and glycogen, respectively.