We applied deuterium oxide–probed stimulated Raman scattering imaging to study metabolic changes of lipids, proteins, and cytochrome c and two-photon excitation fluorescence imaging to assess mitochondrial redox state (nicotinamide adenine dinucleotide and flavin adenine dinucleotide ratio) in ALS cellular models under excess Met treatment. This evidence concerns the gene CYCS and amyotrophic lateral sclerosis.