The total antioxidant capacity in the oocytes were analyzed using Total Antioxidant Capacity Assay Kit with ABTS method (Beyotime, Beijing, China) according to the manufacturer’s protocol. The ABTS test measures the total antioxidant capacity of a sample and it is based on the ABTS• + radical discoloration. The cationic radical ABTS • + is a chromophore that absorbs at a wavelength of 734 nm and is generated by an oxidation reaction of ABTS (2,2ʹ-azino-bis- (3-ethylbenzthiazolin-6-ammonium sulfonate) with potassium persulfate.13 (link)