Bacterial Viability Monitoring via SYBR Green I

Single colonies of BW25113 were inoculated and cultured in LB medium for 12 h as starters of the staining assay. These overnight cultures were aliquoted and treated with or without 5 mM phenformin for 6 or 12 h at 37 °C. Samples from each time point were collected for OD600 measurement and stained with SYBR Green I (MCE, Cat# HY-K1004, 10,000x). Images of bacteria post SYBR Green I staining were acquired with Olympus FV3000-BX63 with 63x immersion objective and analyzed by ImageJ software. More than 3 images per slide were taken for fluorescence quantification.