Biomarker imaging of single diatom cells in a microbial mat using time-of-flight secondary ion mass spectrometry (ToF-SIMS)

► ToF-SIMS used for analysis of biomarkers in a phototrophic microbial mat. ► Biomarkers in extracts and cryosections compared using ToF-SIMS and GC-MS. ► Fatty acids, glycerolipids and pigments in single diatom cells assigned. ► Distribution of fatty acids imaged at the microscopic level.