Sodium disulfite

Experimental procedures were conducted according to the procedures previously described by our laboratory 39 (link). Briefly, 1.5 μl lysis solution (10 mM Tris-HCL; 10 mM EDTA; 1% SDS; 20 μg/ml proteinase K) was added to the collected samples at 37 °C for 1 h, and then NaOH was added to the sample to achieve a final concentration of 0.3M NaOH. Note that the total volume was less than 10 μL. 15 μl melted 2% low gelling temperature agarose (Sigma-Aldrich, USA) was added to the sample and then transferred into pre-cooled mineral oil (Sigma, USA) to form agarose beads. The beads contained the DNA of the cleaved single-oocyte. 5M sodium disulfite (Merck, Germany) was mixed with 1M hydroquinone (Sigma, USA) in a 4:1 ratio and pH value was adjusted to 5. The beads were placed in the mixtures at 50 °C overnight. Some mineral oil was added to prevent evaporation. The beads were washed three times with TE buffer (0.1M Tris-HCl; 0.01M EDTA; pH=8.0). Then they were placed into 0.3M NaOH and rinsed three times for 15 min to remove sulfhydryl, followed by washing with TE and water three times each, and stored at -20 °C.

The reference working standard of hexoprenaline sulphate (purity of 90.3%) was acquired from BOC Sciences (Shirley, NY, USA). The samples of hexoprenaline sulphate as injectable dosage form (10 µg/2 mL) (Gynipral^®) were acquired from Takeda Austria GmbH (Linz, Austria). Sodium chloride, sodium disulfite from Merck (Darmstadt, Germany) and ethylenediaminetetraacetic acid disodium salt dehydrate from Sigma-Aldrich (St. Louis, MO, USA) were used as excipients in the used hexoprenaline product (Gynipral^®), as per the patient information leaflet (PIL) [48 ].