Succinate dehydrogenase activity assay kit

To measure ATP, cells in suspension were mixed with an equal volume of CellTiterGlo in solid white luminescence plates (Grenier Bio-One) according to the manufacturer’s instructions (Promega). Luminescence was measured using a GloMax^® 96 microplate luminometer (Promega) to obtain ATP activity in relative luciferase units (RLU). To measure cellular SDH activity, treated cells were harvested by trypsinization, washed twice in PBS, and subjected to a Succinate Dehydrogenase Activity Assay Kit (K660-100, Biovision) according to the manufacturer’s instructions. The relative SDH activities in tissue were normalized to the citrate synthase activity measured by CS activity kit (K287-100, Biovision) according to the manufacturer’s instructions.

The mitochondrial complex II activity of MCF-7/ADR cells was determined by Succinate Dehydrogenase Activity Assay kit (BioVision). Cells seeded into six-well plates were treated with DT-010, Dox or their combination for 12 h, which were collected for detection of succinate dehydrogenase (SDH) activity according to the manufacturer’s instruction.

The complex II activity of MCF-7 and MDA-MB-231 cells was measured by MTT assay and SDH activity assay kit. According to the MTT assay described previously [14 (link)], cells were seeded into 96-well plates at a density of 6 × 10³/well for 24 h. The cells were exposed to 1 mg/ml MTT in DMEM medium containing 20 mM succinic acid for 2 h at 37°C. The formazan was then dissolved in 150 μL DMSO and the absorbance was measured at 570 nm. For Mitochondrial complex II activity assay, MCF-7 and MDA-MB-231 cells were cultured in 6-well plates for 24 h. The cells were collected and the activity was detected according to Succinate Dehydrogenase Activity Assay kit (BioVision). The absorbance was measured at 600 nm.