PubMed Health⌕ Search

Biomedical subjects

Bong Jin Hong

Publications and source records attributed to Bong Jin Hong.

6 recordsLinked to original sources

Sensitivity enhancement of DNA microarray on nano-scale controlled surface by using a streptavidin-fluorophore conjugate.

High throughput analysis of DNA in low concentration and small volume is an important issue and a continuing challenge in the field of DNA microarray and sensor. Recently, we have demonstrated that the DNA microarray on nano-scale controlled surface provides ample space for hybridization resulting in the best discrimination efficiency for SNP analysis. Here, we report the utility of the nano-scale controlled surface in conjunction with a multiply tagged protein. Application of streptavidin-fluorophore conjugates in combination with the highly controlled surface that suppresses non-specific binding of DNA allows highly sensitive detection of DNA while maintaining superior SNP discrimination efficiency comparable to our earlier results. The sensitivity of DNA microarray on the mesospaced surface is two orders of magnitude higher than that of the generic surface when a streptavidin-fluorophore conjugate was employed, and the detection limit on the former surface was found to be 50 fM of 15-mer target DNA. Various streptavidin-fluorophore conjugates including streptavidin-Cy3, streptavidin-Cy5, streptavidin-Alexa Flour 555 and streptavidin-phycoerythrin were examined.

Anthracenes↗

Surface modification for DNA and protein microarrays.

Microarrays of biomolecules are emerging as powerful tools for genomics, proteomics, and clinical assays, since they make it possible to screen biologically important binding events in a parallel and high throughput fashion. Because the microarrays are fabricated on a solid support, coating of the surface and immobilization strategy of the biomolecules are major issues for successful microarray fabrication. This review deals with both DNA microarrays and protein microarrays, and focuses on the various modification approaches for the two-dimensional surface materials and three-dimensional ones. In addition, the immobilization strategies including adsorption, covalent attachment, physical entrapment, and affinity attachment of the biomolecules are summarized, and advantage and limitation of representative efforts are discussed.

Manufactured Materials↗

DNA microarrays on nanoscale-controlled surface.

We have developed new surface to ensure a proper spacing between immobilized biomolecules. While DNA microarray on this surface provided each probe DNA with ample space for hybridization with incoming target DNAs, the microarray showed enhanced discrimination efficiency for various types of single nucleotide polymorphism. The high discrimination efficiency holds for all tested cases (100:<1 for internal mismatched cases; 100:<28 for terminal mismatched ones). In addition, by investigating influence of hybridization temperature and washing condition on the fluorescence intensity and the discrimination efficiency with and without controlled mesospacing, it was observed that the nanoscale-controlled surface showed good discrimination efficiency in a wide range of temperature (37-50 degrees C), and hybridization behavior on the surface was in agreement with the solution one. Intriguingly, it was found that washing process after the hybridization was critical for the high discrimination efficiency. For the particular case, washing process was so efficient that only 30 s washing was sufficient to reach the optimal discrimination ratio.

Anthracenes↗

DNA microarrays on a dendron-modified surface improve significantly the detection of single nucleotide variations in the p53 gene.

Selectivity and sensitivity in the detection of single nucleotide polymorphisms (SNPs) are among most important attributes to determine the performance of DNA microarrays. We previously reported the generation of a novel mesospaced surface prepared by applying dendron molecules on the solid surface. DNA microarrays that were fabricated on the dendron-modified surface exhibited outstanding performance for the detection of single nucleotide variation in the synthetic oligonucleotide DNA. DNA microarrays on the dendron-modified surface were subjected to the detection of single nucleotide variations in the exons 5-8 of the p53 gene in genomic DNAs from cancer cell lines. DNA microarrays on the dendron-modified surface clearly discriminated single nucleotide variations in hotspot codons with high selectivity and sensitivity. The ratio between the fluorescence intensity of perfectly matched duplexes and that of single nucleotide mismatched duplexes was >5-100 without sacrificing signal intensity. Our results showed that the outstanding performance of DNA microarrays fabricated on the dendron-modified surface is strongly related to novel properties of the dendron molecule, which has the conical structure allowing mesospacing between the capture probes. Our microarrays on the dendron-modified surface can reduce the steric hindrance not only between the solid surface and target DNA, but also among immobilized capture probes enabling the hybridization process on the surface to be very effective. Our DNA microarrays on the dendron-modified surface could be applied to various analyses that require accurate detection of SNPs.

Anthracenes↗

Nanoscale-controlled spacing provides DNA microarrays with the SNP discrimination efficiency in solution phase.

We have prepared solid substrates modified with a cone-shaped dendron that generates mesospacing (3.2 nm on average) on the surface. This nanoscale-controlled surface provided an ideal DNA microarray in which each probe DNA strand was given ample space for the incoming target DNA, resulting in selectivity as high as that in solution (100: < 1). In addition, high hybridization yield confirms that DNA probes on the mesospaced surface are sterically unhindered for the hybridization.

Base Sequence↗