Resumo (PT):
Abstract (EN):
In the past few years, several researchers have focused their attention on nucleic acid mimics due to the increasing necessity of developing a more robust recognition of DNA
or RNA sequences. Fluorescence in situ hybridization (FISH)
is an example of a method where the use of these novel nucleic
acid monomers might be crucial to the success of the analysis.
To achieve the expected accuracy in detection, FISH probes
should have high binding affinity towards their complementary strands and discriminate effectively the noncomplementary strands. In this study, we investigate the effect of different
chemical modifications in fluorescent probes on their ability
to successfully detect the complementary target and discriminate the mismatched base pairs by FISH. To our knowledge,
this paper presents the first study where this analysis is performed with different types of FISH probes directly in biological targets, Helicobacter pylori and Helicobacter
acinonychis. This is also the first study where unlocked
nucleic acids (UNA) were used as chemistry modification in
oligonucleotides for FISH methodologies. The effectiveness
in detecting the specific target and in mismatch discrimination
appears to be improved using locked nucleic acids (LNA)/2′-
O-methyl RNA (2′OMe) or peptide nucleic acid (PNA) in
comparison to LNA/DNA, LNA/UNA, or DNA probes.
Further, the use of LNA modifications together with 2′OMe
monomers allowed the use of shorter fluorescent probes and
increased the range of hybridization temperatures at which
FISH would work.
Language:
English
Type (Professor's evaluation):
Scientific
No. of pages:
9