n Applications in Genetics
a. WUd type probe 2841G
b. Mutant probe 284 IT
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TtIIlperature ("q
49 51
53 55 57 59 61 63 65 67 69
TtIIlperature ("q
c. WUd type probe 35l9G
d. Mutant probe 3519T
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TtIIlperature ("q
53 55 57 59 61
63 65 67 69 7 1
TtIIlperature ("q
-
Normal DNA
-
HeterO%YIIOUS
- n o DNA
I Wid type peak
I Mutantpeak
Fig 1. Detection of the 2841GT (fig.lA,B) and 3591GT (fig. 1 C,D) mutations in DNA from blood
from a normal control person and from two carriers of a mutation. The heterozygous carriers
show two peaks with wild type probe as well as mutant probe. The homozygous normal shows
a single peak in all cases. With the wild type probes (A, C), the mutant peak shifts to the left,
whereas the mutant probes show a shift to the left of the wild type peak (B, D)
shows that a combination of wild-type and mutant probes may be more specific
in determining the presence or absence of a known mutation. If the technique is
used in preimplantation diagnosis to detect mutations in single cells from
embryos prior to implantation, it is most important to assess cells that do not contain the mutation. Possible false positives due to a PCR mutation in the probebinding area in the very first cycle of PCR are no problem, because only negative
embryos are used for implantation.
The whole procedure, from selecting the cells until the final results takes less
than 1 h. Consequently, the technique has great potential in fields where reliable
and extremely fast mutation detection is important, such as preimplantation
diagnosis.