PubMed Health⌕ Search

Biomedical subjects

Michinori Waki

Publications and source records attributed to Michinori Waki.

7 recordsLinked to original sources
PubMed2007

Direct modification of mRNA by ferrocenyl carbodiimide and its application to electrochemical detection of mRNA.

Ferrocenyl carbodiimide (1) could be used for the direct labeling of synthetic RNA and expressed mRNA in vitro with the electrochemically active ferrocene moieties. These RNAs modified by 1 could be detected electrochemically coupled with a DNA probe-immobilized electrode. After hybridization of 1.1 Kb mRNA modified by 1 with the DNA probe-immobilized electrode, the peak charge observed by an Osteryoung square wave voltammetry (SWV) measurement correlated well with the concentration of mRNA, having a detection limit at the sub nanogram level.

Carbodiimides↗
PubMed2006

Electrochemical detection of DNase I activity.

DNase I in one microl of the water could quantitate electrochemically with the detection limit of 0.01 units (ca. 20 pg) by using the ferrocenyl oligonucleotide-immobilized electrode prepared by thiolated oligonucleotide and ferrocenyl carbodiimide as a simple labeling reagent of redox unit.

Carbodiimides↗
PubMed2006

Electrochemical SNP detection.

Detection of mismatched base on a DNA duplex, which is important for the search of the heterozygote, achieved by the comparison with the reactivity of ferrocenylcarbodiimide (1) developed by our group. Mismatched thymine base on the 30-meric DNA duplex as a model of SNPs in lipoprotein lipase (LPL) gene, could react with 1 in 20 mM borate buffer (pH 8.5) and 0.1 M NaCl containing 20% DMSO at 37 degrees C. DNA duplex modified by 1 in the mismatched thymine bases could be detected by its shifted migration time in microTAS electrophoresis.

Base Pair Mismatch↗
PubMed2005

Immobilization of RNase S-Peptide on a single-stranded DNA-fixed gold surface and effective masking of its surface by an acridinyl poly(ethylene glycol).

Oligonucleotide-peptide conjugate was synthesized by coupling of RNase S-peptide to a 24-mer single-stranded DNA (ssDNA) oligonucleotide to be immobilized on its complementary ssDNA oligonucleotide-fixed gold surface of sensor chip or electrode. Immobilization of on the ssDNA-fixed gold surface through DNA duplex formation was confirmed by quartz crystal microbalance (QCM) and electrochemical measurements. After treating with a synthetic acridinyl poly(ethylene glycol) (APEG), specific interaction of S-protein with the S-peptide immobilized on the gold surface was demonstrated by QCM without nonspecific adsorption of unrelated proteins such as BSA and RNase A at the surfaces. This result suggested that the acridine parts of APEG could bind to the DNA duplex on the gold surface and the poly(ethylene glycol) parts were fastened on the surface to resist the adsorption of proteins. Thus, the combination of oligonucleotide-peptide conjugate, ssDNA-fixed chip and APEG with effective masking property provides a new tool for the analysis of specific peptide-protein interactions without disturbance by other unrelated proteins.

Acridines↗
PubMed2005

Interaction analysis of the carcinoembryonic antigen (CEA) with its monoclonal antibody immobilized on a gold surface using Fourier transform infrared reflection-absorption spectroscopy (FT-IR RAS).

A monoclonal antibody for the carcinoembryonic antigen (CEA) was immobilized on a gold chip surface covered by a self-assembled monolayer of 11-mercaptoundecanoic acid. Upon the addition of CEA, a Fourier transform infrared reflection-absorption spectroscopy (FT-IR RAS) measurement showed an increased absorption at around 1500 - 1700 cm(-1), corresponding to its amide structures. Another addition of CEA polyclonal antibody on this chip caused a further increase of the absorption in this region only after a treatment with CEA. This result shows that an antibody-fixed gold surface coupled with an FT-IR RAS measurement provides a new tool for detecting the antibody-antigen interaction.

Antibodies, Monoclonal↗