Osmium tetroxide stock solution (2%)

MATERIALS

METHOD

Perform all steps in a fume hood. Wear rubber gloves and goggles.

• 1. Pour 50 mL of H₂O into a wide-necked brown glass bottle that can be sealed by a ground-glass stopper.

• 2. Place the bottle in a polystyrene box.

• 3. Submerge a glass ampoule containing 1 g of osmium oxide in the H₂O.

• 4. Break the ampoule with a metal rod.

• 5. Stopper the bottle. Incubate for 10 min in an ultrasonic bath.

• 6. Wrap the bottle with aluminum foil. Incubate overnight in the fume hood to allow the osmium oxide to dissolve completely.

  Stored refrigerated at 4°C for up to 6 wk.