[lab2015]

I need to dilute my samples with 0.01 mol/L PBS (pH=7.0 - 7.2)
I have a 10x  PBS :
1x (pH = 7.4±0.1) contains:
11.9 mM Phosphate
137 mM Sodium Chloride
2.7 mM Potassium Chloride

it looks like it has the concentration that I need.

Would you please tell me if this is right? should the diffrence in pH be corrected? I need pH= 7 to 7.2 while the pH here is 7.4±0.1

Many thanks,

[Yggdrasil]

You probably would not have problems using a pH 7.4 buffer versus ph 7.2.

[Babcock_Hall]

If you dilute a 10X buffer to 1X, the pH should move somewhat.  One reason is that the change in ionic strength affects the practical pK_a value.  Dilution of an acidic buffer increases the pH; basic buffers should behave oppositely.  Both Perrin and Boyd's book and Beynon and Easterby's book mention this effect.  The change in pH upon dilution might be small enough not to worry about, but there is no harm in being aware of it.

[lab2015]

You probably would not have problems using a pH 7.4 buffer versus ph 7.2.

Thank you for your reply