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Biomedical subjects

Yuji Ochi

Publications and source records attributed to Yuji Ochi.

7 recordsLinked to original sources

Simple SNP typing assay using a base-discriminating fluorescent probe.

We have developed a new concept involving a single-step homogeneous method for single-nucleotide polymorphism (SNP) typing. In this method, a probe containing base-discriminating fluorescent (BDF) bases is added to a sample solution. BDF base-containing DNA usually shows only a weak fluorescence, but emits a strong blue fluorescence when it recognizes a target base at a specific site in a hybridized strand. By utilizing this feature, a simple mix-and-read SNP typing assay was achieved without any tedious probe-designing or washing processes for exclusion of hybridization error or any addition of DNA-modifying enzymes. This is very different from conventional methods. We simultaneously analyzed a number of samples with ease, with a high accuracy, using our BDF assay.

Base Sequence↗

SNPs typing by base-discriminating fluorescence DNA probe.

For the development of a novel SNP typing method using BDF (base-discriminating fluorescent) nucleosides in biological samples, we examined the detection of the single base alteration in BRCA1 gene with PCR products amplified by an asymmetric PCR. A combination of PyU- and PyC-containing BDF probes clearly facilitates the discrimination of not only A/G homozygous samples but also heterozygous samples. The present SNP typing method with BDF probes is a very powerful homogeneous assay that does not require a special device or time-consuming steps.

DNA Probes↗

Design of base-discriminating fluorescent (BDF) nucleobase for SNP typing.

We have devised novel pyrene-labeled BDF nucleosides, (Py)U, (Py)C, (Py)deazaA, and (Py)A. BDF probes containing these fluorescent nucleosides selectively emit fluorescence only when the base opposite the BDF base is a target base. Oligonucleotides containing these BDF nucleosides act as effective reporter probes for homogeneous SNP typing of DNA samples.

Fluorescent Dyes↗

Fluorescent probe for the detection of DNA conformational transition.

Two pyrene-labeled bases, (py)C and (8py)G, have been synthesized and incorporated into d(CG)n. In the CD spectra, structural transition of a modified oligodeoxynucleotide (ODN-Py) from B-form to Z-form has been observed under different salt concentrations. The conformational transition of ODN-Py was monitored by the change of emission wavelengths based on exciplex and monomer fluorescence of (py)C and (8py)G.

Cytosine↗

DNA nanomotor using duplex-quadruplex conformational transition.

For DNA nanomotor, we synthesized 8-Py-dG and incorporated it into d(T3G2)4 which can form quadruplex. We measured CD spectra for this ODN. The result suggested that this ODN was changed from quadruplex to duplex by the hybridization with the complementary strand. Further, this ODN had a very interesting property of fluorescence. The fluorescent intensity could be controlled whether the complementary strand was existed, or not.

Base Sequence↗