We normally add potassium phosphate buffer (pH 6.0) to NGM. However, in some of the more recent publications i observe that they have done away with KPO4 buffer. Instead they just add 1M KH2PO4 (potassium dihydrogen phosphate) at pH 6.0. Does any one know why this sudden change in recipe? I was just curious if the change had to do something with the worm’s health or is it just a standard practice?
These two buffers are the same thing. Remember your chemistry 101: You can prepare a pH 6 potassium phosphate buffer by dissolving K2HPO4 and adding acid to pH 6; by dissolving KH2PO4 and adding base to pH 6; or by dissolving a mixture of K2HPO4 and KH2PO4, calculating the amounts so as to achieve a pH of 6. All of these yield an identical pH 6 phosphate buffer.
What Dan said. Also found in various protocols as “KPi”