Infinite 200 pro multi function microplate reader

The triglyceride and cholesterol concentrations in hepatocytes were measured 48 hours after transfection using the cell triglyceride and cholesterol assay kit (Applygen Technologies, Beijing, China), according to instructions.
Firstly, after removal of spent medium, the cells were washed three times with PBS and 300 μl of lysate (the amount of lysate added depending on the cell density) were added and allowed to stand for 10 minutes. The cells were collected, mixed, centrifuged, and the supernatant was used for protein quantification. The supernatant was warmed to 70 °C, centrifuged at 2000 rpm for 5 minutes, and the retaining the supernatant. Fifty microliters of the supernatant were added each well of an ELISA plate, using a blank control group and three replicates of each sample. After addition of 150 μl of working solution and allowing to react for 10 minutes at 37 °C, the absorbances at 550 nm were measured using a microplate reader (Infinite 200 PRO multi-function microplate reader, Tecan, Switzerland), and the triglyceride and cholesterol concentrations were calculated using the standard curve and expressed in terms of the protein concentrations.

In the process of the experiment, a 3 mL algae culture medium was extracted from each Erlenmeyer flask to measure oxidative stress biomarkers at 11 days. The samples needed to be pretreated before the measurement of oxidative stress biomarkers, and the culture medium was centrifuged at 4000 rpm for 10 min. The supernatant was discarded. The cell pellet was resuspended in 1 mL of normal saline to wash, centrifuged again at 1000 rpm for 10 min, and the supernatant was discarded. The wash operation was repeated three times. A 2 mL volume of normal saline was added to the cell pellet then mixed well and homogenized manually, 1 min at a time at 30 s intervals, and repeated 6–8 times. Oxidative stress biomarkers were measured using a Tecan Infinite^® 200 Pro Multifunction microplate reader (Tecan Austria GmbH, Grödig, Austria). Measurement of oxidative stress biomarkers was strictly performed according to the manufacturer’s instructions.