Oocyte Reagent 2 (O-R2)

• 1. Prepare Stock Solution A by dissolving the following reagents in deionized H₂O for a final volume of 1 L. Store indefinitely at 4°C–8°C.

  HEPES	11.915 g
  NaCl	48.221 g
  KCl	1.864 g
  CaCl2 · 2H2O	1.47 g
  MgCl2 · 6H2O	2.03 g
  NaOH	1.520 g

• 2. Prepare Stock Solution B by dissolving 1.420 g of Na₂HPO₄ in deionized H₂O for a final volume of 1 L. Store indefinitely at 4°C–8°C.

• 3. Combine 100 mL of Stock Solution A, 100 mL of Stock Solution B, and 800 mL of deionzed H₂O. Add antibiotics. Store for up to 1–2 mo at 16°C–18°C (the same temperature used for oocyte incubation). Check before use.

  • The pH should be 7.8. The final reagent concentrations are 5 mm HEPES, 82.5 mm NaCl, 2.5 mm KCl, 1 mm CaCl₂, 1 mm MgCl₂, 3.8 mm NaOH, and 1 mm Na₂HPO₄.

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