Long PCR Buffer

Long PCR Buffer
In our hands tricine buffer works well with Tth but not as well with Taq. The pH is probably critical to the efficiency of amplification of long targets (1).

1X Long PCR Buffer
85 mM KOAc
25 mM Tricine pH 8.7 (adjust pH of Tricine stock solution with KOH)
8% glycerol
1% DMSO (1 to 4% works)
1.2 mM Mg(OAc)2
A 5X buffer stock containing 6 mM Mg(OAc)2 (1.2 mM final concentration) and 5% DMSO (1% final concentration) can easily be made using 500 mM Mg(OAc)2, 1 M Tricine and 1 M KOAc stock solutions as follows:

5X Long PCR Buffer
425 mM KOAc
125 mM Tricine pH 8.7 (adjust pH of Tricine stock solution with KOH)
40% glycerol
5% DMSO
6.0 mM Mg(OAc)2

10 ml 5X buffer
4.25 ml 1M KOAc
1.25 ml 1M Tricine, pH8.7 @ 25 degrees C (with KOH)
4.00 ml glycerol
0.50 ml DMSO
120 ul 500 mM Mg(OAc)2