Other TC Solutions

Phosphate buffered saline (PBS)

  1. Dissolve 8 tablets of PBS tablets into 2L of ELGA water in a large beaker (1 tablet/250mL) on a stir plate.

  2. Cover the beaker with aluminum foil to prevent dust settling

  3. After the solids are completely dissolved, adjust the pH of the solution to 7.4 by adding NaOH or HCl dropwise.

  4. Keep stirring the PBS while adjusting the pH and keep measuring the pH until it completely equilibrates.

  5. Transfer pH-adjusted PBS into 500mL or 1L bottles, label and mark with autoclave tape, and autoclave in liquid cycle.

0.1% Gelatin

  1. Dissolve 0.5 g gelatin (Type A, from porcine skin) (Sigma G1890) into 500uL ELGA water in an autoclavable glass bottle. Scale volume as needed.

  2. Label appropriately and mark with autoclave tape before autoclaving in liquid cycle.

EDTA (0.5M, pH=8.0)

To make 50 mL of EDTA using Ethylenediaminetetraacetic acid (EDTA) disodium salt dihydrate (MW: 372.24 g/mol). Note - EDTA disodium salt dihydrate MW is higher than just EDTA.

Solution is stable at 4°C for months.

  1. Clean a stir bar and add to 100 mL glass beaker.

  2. Add 9.306 g EDTA disodium salt dihydrate to 40 mL of ELGA water to beaker.

  3. Adjust the pH of the solution to 8.0 by adding NaOH dropwise. Be aware you’ll have to use quite a bit of NaOH and the EDTA will dissolve as the pH increases. You’ll need roughly 1-2 mL 12N NaOH.

  4. Keep stirring while adjusting the pH and keep measuring the pH until it completely equilibrates and dissolves. It will take >5 min for solution to become clear and >10 min for all sediment to dissolve.

  5. Transfer pH-adjusted EDTA to a 50 mL conical and add ELGA water to 50 mL.

  6. Take into TC and sterilize by filtering through a 0.22 µm filter.