A commonly used PCR buffer, includes only KCl, Tris and MgCl2 (for example, Perkin Elmer Cetus); a somewhat more complex buffer was previously proposed for multiplex reactions of the DMD gene exons (Chamberlain et al. (1988) in Nucleic Ac Res 16: 11141-11156). These buffers were compared in multiplex PCR reactions, for their efficiency in supporting the activity of the Taq polymerase. Figure 15 shows that, PCR reactions on four different genomic DNA templates were consistently more efficient (more PCR product) when performed in 1.6x PCR buffer than 1x DMD buffer. Same amount of template DNA and primer were taken in all reactions, which were run in the same conditions at the same time. The same amount of product was loaded in each lane on the gel. Table 3.Comparison of PCR buffers.| 10xPCR buffer | 5xDMD buffer | - 500 mM KCl
- 100 mM Tris-HCl (pH 8.3)
- 15 mM MgCl2
| - 83mM (NH4)2SO4
- 335mM Tris-HCl (pH8.8)
- 33.5mM MgCl2
- 50mM ß-Mercapthoethanol
- 34 mM EDTA
| - optimal dNTP concentration in the reaction = 200 mM
| - optimal dNTP concentration in the reaction = 6000 mM
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