I've been trying to work out a suitable buffer for my microbe experiment, which has forced me to try and remember my high school chemistry. I understand the basic principal of how a molecule can act as a conjugate base/acid. I've spent a good hour Googling and discussing this with fellow grad-students in my lab, but apparently apart from our own specialised fields, we've forgotten how to tie our shoe laces.

My question is, when we have a mixture as a buffer, e.g. KH2PO4 K2HPO4 (can't seem to get the subscript going...), what's happening here? Apart from being able to adjust the pH by changing the ratio of the primer buffer (how does that work?), is there any increase in buffer capacity or range?

Thank you.

EDIT: Wow, I typed primer instead of buffer... too much PCR in my blood.