POTASSIUM PHOSPHATE BUFFER (for NGM plates)

1) Make the following two solutions separately, then mix to obtain correct pH (6.0).

A. 250 ml 1M KH₂PO₄

Add dH₂O to 34.0 g KH₂PO₄ until final volume (250 ml) is obtained

B. 200 ml 1M K₂HPO₄·H₂O

Add dH₂O to 45.6 g K₂HPO₄

*Make sure the salt in the solutions is completely dissolved.

2) Add K₂HPO₄ solution to KH₂PO4 solution to bring the pH up from 4.0 to 6.0 (will take about 100 ml of K₂HPO₄).

3) Divide phosphate buffer into aliquots of 50-100 ml.

4) Autoclave 15 min. liquid cycle

5) Store at room temperature.