Infinite 200 pro series multimode reader

In 96-well plates, 20 μL of each sample (6.25–200 μM) was mixed with 80 μL of 100 mM Tris-HCl buffer at pH 7.4 and 100 μL of 200 μM DPPH ethanol solution. The mixtures were incubated at room temperature (RT) for 20 min in darkness, and the absorbance at 517 nm was then measured using a microplate reader (Infinite 200 PRO Series Multimode Reader; TECAN, Switzerland). The DPPH radical scavenging effect was calculated using the following equation: [(A0–As)/A0] × 100, where A0 is the absorbance of the control reaction and As is the absorbance of the sample. The experiments were performed in triplicate.

Cell viability was quantified using MTT (Enzo Life Sciences, Inc., Farmingdale, PA, USA) reduction assay. The cells were pre-incubated overnight in 24-well plates at a density of 6 × 10⁴ cells/well. Cisplatin and/or fucoidan were added at various concentrations after 24 h. After the cells were subjected to different treatments, MTT solution was added at a final concentration of 0.2 mg/mL for 4 h at 33 °C, and the formazan crystals were dissolved in 200 μL dimethyl sulfoxide. The absorbance was measured at 570 nm using a microplate reader (Infinite 200 PRO Series Multimode Reader; Tecan, Männedorf, Switzerland).