Chameleon Emulsion (in Japanese)

example, DNA oligomers fold long single-stranded DNA, which serves as a template, into arbitrary shapes by combining short strands of DNA (stapled DNA) that are complementary to specific sequences in the DNA. Our research focuses on the characteristic branching structures (replication forks or Holliday junctions) that occur during the DNA replication process. Here, we focused on the phenomenon of self-organized association of DNA double helices with trigeminal structures. However, since the association of DNA is reversible, it dissociates at high temperatures or in solutions with low ionic strength. Therefore, we combined it with a low molecular weight compound (psolaren) that can cross-link DNA strands by generating covalent bonds through photoreaction. As a result, we discovered that the DNA can grow to submicron size by generating hyperbranched polymers on the substrate surface. It is expected to be used as a single molecule electronic material in the future.
 

infectious pathogens, by producing antibodies. Antibodies precisely recognize and bind to foreign substances, so they can be artificially produced for a variety of uses. The enzyme immunoassay is a typical example of such a method, which enables highly sensitive and selective analysis. We have been conducting research on a new analytical system, the microfluidic analysis system, which integrates a series of analytical operations, such as sample introduction, separation, and detection, into a single palm-sized substrate. This time, we have established a system that incorporates enzyme immunoassay and developed a high-performance method for the analysis of pesticide residues. Using this system, there is no need for expensive and large analyzers. It can be brought to the site where analysis is required and measured on the spot. Therefore, it is expected to be applied to environmental analysis in the future.
 

including probe DNA and labeled DNA for electrochemical detection. DNAs do not exert any catalytic reaction that are observed in enzymes. Moreover, the guanine bases are easily degraded by redox reactions, making it difficult to detect using common assays in biosensors. Here, the target DNA contains a genetically meaningful sequence (gene) and an associated sequence. We have devised a method in which a third DNA fragment is labeled with a redox-active small molecule compound in addition to the DNA fragment used to recognize the former (DNA probe). If the sequence is complementary to the sequence associated with the gene, a hybridization product consisting of three DNA strands is generated, as shown in the figure, and the target DNA can be detected electrochemically. If the target DNA contains a single nucleotide polymorphism, the measurement conditions could be set so that hybridization does not occur.
 

by Watson and Crick (1953), research on artificial nucleic acids or nucleic acid analogs began. Peptide nucleic acids (PNAs) are one such type of nucleic acid, in which nucleobases are linked via amide bonds, the same as in peptides, instead of the phosphate diester bonds found in nucleic acids. On the other hand, as seen in ribozymes, nucleic acids are often involved in biological phenomena by expressing enzymatic functions. This deviates from the route of enzyme production by transcription of nucleic acids, which has led to a discussion comparing the relationship between nucleic acids and enzymes to that of an egg and a chicken. Focusing on the structure of PNA, we have proposed an artificial nucleic acid catalyst, PNAzyme, which is synthesized by integrating a catalytic peptide. We have succeeded in synthesizing a PNAzyme that exhibits peroxidase activity, and have reported its application to bioanalysis.