Invitrogen's 2X PCR Mix

Invitrogen/Life Technology's  stable 2X mix
1:
20 mM Tris—HCl,pH 8.4
50 mM KCl
0.1% Tween20 or NP40 
Taq 20 units
3 mM MgCl2
200 uM dNTP

2:
66 mM Tris—S04 (pH 9.1) 
19.8 mM (NH4)2S04
2.2 mM MgSO4
22 units/ml Taq DNA Polymerase
0.22 units/m1 DEEPVENT DNA Polymerase
0.11% Tween—20
0.011% NP-40 

Stability

Room Termperature:  <12 weeks 
4 oC:               11 months

3:
66 mM Tris—S04 (pH 9.1)
19.8 mM (NH4)2S04
2.2 mM MgSO4
24.42 units/ml Taq DNA Polymerase
0.242 units/m1 DEEPVENT DNA
Polymerase
0.066% Tween—20
0.066% NP-40 

Stability

Room Termperature:  <12 weeks 
4 oC:               >11 months