Biomedical subjects

Kimimichi Obata

Publications and source records attributed to Kimimichi Obata.

4 recordsLinked to original sources

PubMed2004

Three-dimensional microarray platform applied to single nucleotide polymorphism analysis.

Bio-Strand, Inc., has developed a novel DNA microarray platform utilizing a three-dimensional (3D) DNA format. DNA probes or polymerase chain reaction (PCR) products are spotted onto a thread-like scaffold, which is then wound onto a cylindrical core. By wrapping the thread around the core, high efficiencies are achieved in sample analysis. Using allele-specific oligo (ASO) competitive hybridization (with Cy5 fluorescently labeled sequences), hybridized arrays are visualized using a helium-neon (HeNe) laser and quantitated/scored. The method can readily detect single nucleotide differences. We demonstrate the use of this Bio-Strand 3D array in the analysis of a single nucleotide polymorphism (SNP).

Carbocyanines↗

PubMed2004

Development of an integrated automation system with a magnetic bead-mediated nucleic acid purification device for genetic analysis and gene manipulation.

We have developed an integrated automation system for genetic analysis and gene manipulation. The system, SX-8G Plus, is equipped with an 8-nozzle dispensing unit, a thermal cycler, a cooled reagent reservoir, four tip storage racks, four microplate platforms, buffer reservoirs, an agarose gel electrophoresis unit, a power supply, a pump for exchanging electrophoresis buffer, and a CCD camera. Automation of nucleic acid extraction and purification, the most difficult step in automating genetic analysis and gene manipulation, was realized using magnetic beads with Magtration Technology, which we have previously developed for automating the handling of paramagnetic beads. Using this system, we could perform the automated separation and purification of DNA fragments by agarose gel electrophoresis starting from sample loading. The system would enable the automation of almost all procedures in genetic analysis and gene manipulation.

Computers↗

PubMed2004

Rapid and sensitive detection of 17beta-estradiol in environmental water using automated immunoassay system with bacterial magnetic particles.

A fully automated immunoassay of 17beta-estradiol (E2) was performed using anti-E2 monoclonal antibody immobilized on bacterial magnetic particles (AntiE2-BMPs) and alkaline phosphatase-conjugated E2 (ALP-E2). E2 concentration in environmental water samples was evaluated by decrease in luminescence based on competitive reaction. A linear correlation between the luminescence intensity and E2 concentration was obtained between 0.5 and 5 ppb. The minimum detectable concentration of E2 was 20 ppt. All measurement steps were done within 0.5 h. The analysis of environmental water samples by a commercially available ELISA kit and the BMP-based immunoassay gave good correlation plots with a correlation efficient of 0.992. These results suggest that the fully automated system using the BMP-based immunoassay has some advantages in the high rapidity and sensitivity of the measurement. This system will enable us to determine low E2 concentrations without sample condensation.

Bacterial Proteins↗

PubMed2002

Recent developments in laboratory automation using magnetic particles for genome analysis.

The majority of research for genome analysis has shifted from nucleic acid sequencing to the biological functional analysis of each gene. Based on past success, it may not be long before genome diagnostics becomes a widespread tool in human, veterinary and botany research fields. Genome analysis involves the processes of nucleic acid purification, amplification, labeling and signal detection (specific reaction, separation and signal counting). Except for the purification of nucleic acids, the other processes cannot be achieved without instruments, resulting in the advancement of automation processes. Since purification of nucleic acids can be done manually, automating this process has been delayed. However, because the purification of nucleic acids using magnetic particles is suitable for automation, its development has also been accelerated. The need for full automation for other processes is not as great because the majority of genome analysis is to identify the nucleic acid sequence and analyze genome expression. However, once useful diagnostic tools are generated, the desire for full automation will significantly increase. In order to develop realistic and practical automation, various technologies developed for each process in genome analysis have to be evaluated and only a few technologies, useful for automation, selected. The other key factor in automation is the development of methods to manage reagents and reaction mixtures precisely without any risks specifically related to genome handling, such as cross-contamination. Methods using magnetic particles, which have been used for the automation of nucleic acid purification and immunoassay, appear to be the most promising way to automate processes used in biological research.

Animals↗