3 replies to this topic

[saad]

Hi Guys

I know that I need to prepare mono and dibasic potassium phosphate then mix as .... to get the right pH.
I prepared 50 mM, 500 mM NaCl ... potassium buffer just from K2HPO4 then I adjusted the pH with HCl till pH7.5.
Do you know if this could be buffered.
Thanks a lot.

[mdfenko]

use of mono and dibasic phosphate solutions to prepare buffer is an easy way to make the buffer at a given concentration regardless of the final volume. this method is often used to prepare concentrated stock solutions.

adjusting one component with an acid or base (depending on which) is another way to prepare the buffer but you have to adjust the final volume to obtain the desired concentration. buffering effect is determined by the pH.

[saad]

Thank you mdfenko for this clarifying.
I've heard that it's not good to dilute from 10x stock buffer. i mean if I prepare 1M (KH2PO4/K2HPO4) then I want to make 50 mM from the stock by dilution with MQW and add the other components of buffer and adjust the pH depending on which. Is it OK like that.

Thank you so much.

[mdfenko]

we make a 1M stock and dilute as necessary.