Bio-Rad DCode™ Universal Mutation Detection System - Manual (Page 14)

Fig. 4.3. The example betaglobin sequence with a 40 bp GC clamp attached to the 3’ end.
Figure 4.4 shows the melting profile for the 339 base-pair GC clamped betaglobin sequence
using the 50% probability. From the melting profile, it can be seen that there is now one low
melting region and a high melting region that is formed by the GC clamp. The melting profile
shows how the addition of the GC clamp lowered the theoretical melting temperature of bases
80 to 185 shown in Figure 4.2. The GC clamp can also be tried on the 5' end of the sequence.
Fig. 4.4. The melting profile of the example betaglobin sequence with a 3' GC clamp attached.
The graph in Figure 4.5 shows different melt profiles for a mutant betaglobin sequence
with a "T to G" mutation at base 51 and the wild-type sequence. The difference in the melt
profile between the two sequences is easily seen when the axis is changed to show the 1 to
136 base-pair region. Since it is possible to see a different melt profile for the mutant and
wild-type sequences using the software, it should therefore be possible to resolve the mutant
and wild- type sequences on a DGGE gel.
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