Shin S.,KAIST |
Won B.Y.,KAIST |
Jung C.,KAIST |
Shin S.C.,KAIST |
And 3 more authors.
Chemical Communications | Year: 2011
Utilizing a peptide nucleic acid (PNA)-modified electrode and a single-stranded DNA specific endonuclease, a novel electrochemical method to identify DNA mutations has been developed and represents a totally new strategy for the electrochemical diagnosis of human genetic mutations. © 2011 The Royal Society of Chemistry.
Kim M.I.,KAIST |
Yu B.J.,MD Science Inc. |
Woo M.-A.,KAIST |
Cho D.,LabGenomics Co. |
And 4 more authors.
Analytical Chemistry | Year: 2010
We describe a novel multiplex "amino acid array" for simultaneously quantifying different amino acids based on the rapid growth of amino acid auxotrophic E. coli. First, we constructed genetically engineered amino acid auxotrophs of E. coli containing a bioluminescence reporter gene, yielding concomitant luminescence as a response to cell growth, and then immobilized the reporter cells within individual agarose of respective wells in a 96-well plate serving as a mimic of a biochip. Using the amino acid array, we were able to determine quantitatively the concentrations of 16 amino acids in biological fluid by simply measuring bioluminescent signals from the immobilized cells within 4 h without pre- and post-treatment. The clinical utility of this method was verified by quantifying different amino acids in dried blood spot specimens from clinical samples for the diagnosis of metabolic diseases of newborn babies. This method serves as a convenient route to the rapid and simultaneous analysis of multiple amino acids from complex biological fluids and represents a new analytical paradigm that can replace conventional, yet laborious methods currently in use. © 2010 American Chemical Society.
Jung Y.L.,KAIST |
Jung C.,KAIST |
Parab H.,KAIST |
Cho D.-Y.,LabGenomics Co. |
ChemBioChem | Year: 2011
Red gold/blue gold: A highly convenient colorimetric method for the identification of single-nucleotide polymorphism was developed by utilizing gold nanoparticles and an allele-specific polymerase chain reaction. Its diagnostic capability was successfully demonstrated by correctly identifying various mutations in the BRCA1 gene. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Woo M.-A.,KAIST |
Woo M.-A.,Korea Food Research Institute |
Kim M.I.,KAIST |
Cho D.,LabGenomics Co. |
Analytical Chemistry | Year: 2013
A new cell-based galactose assay system, which is comprised of two bioluminescent Escherichia coli strains immobilized within an agarose gel arrayed on a well plate, has been developed. For this purpose, a galT knockout strain [galT(-) cell] of E. coli was genetically constructed so that cell growth is not promoted by galactose but rather by glucose present in a sample. Another E. coli W strain (normal cell), which grows normally in the presence of either glucose or galactose, was employed. A luminescent reporter gene, which produces luminescence as cells grow, was inserted into both of the E. coli strains, so that cell growth could be monitored in a facile manner. The two strains were separately grown for 4 h on gel arrays to which test samples were individually supplied. The relative luminescence unit (RLU) values caused by cell growth were determined for each array, one of which is resulted by glucose only and the other of which is resulted by both glucose and galactose present in the sample. By employing this protocol, galactose concentrations present in the test sample are reflected in the differences between the RLU values for each array. The practical utility of the new assay system was demonstrated by its use in determining galactose levels in clinical blood spot specimens coming from newborn babies. Because it can be employed to diagnosis of galactosemia in newborn babies in a more rapid, convenient, and cost-effective manner, this cell-based solid-phase galactose assay system should become a powerful alternative to conventional methods, which require labor-intensive and time-consuming procedures and/or complicated and expensive equipment. © 2013 American Chemical Society.
PubMed | KAIST, Korea University, Gachon University and LabGenomics Co.
Type: Journal Article | Journal: Analytical chemistry | Year: 2016
We developed a whole-cell surface plasmon resonance (SPR) sensor based on a leucine auxotroph of Escherichia coli displaying a gold-binding protein (GBP) in response to cell growth and applied this sensor to the diagnosis of maple syrup urine disease, which is represented by the elevated leucine level in blood. The leucine auxotroph was genetically engineered to grow displaying GBP in a proportion to the concentration of target amino acid leucine. The GBP expressed on the surface of the auxotrophs directly bound to the golden surface of an SPR chip without the need for any additional treatment or reagents, which consequently produced SPR signals used to determine leucine levels in a test sample. Gold nanoparticles (GNPs) were further applied to the SPR system, which significantly enhanced the signal intensity up to 10-fold by specifically binding to GBP expressed on the cell surface. Finally, the diagnostic utility of our system was demonstrated by its employment in reliably determining different statuses of maple syrup urine disease based on a known cutoff level of leucine. This new approach based on an amino acid-auxotrophic E. coli strain expressing a GBP that binds to an SPR sensor holds great promise for detection of other metabolic diseases of newborn babies including homocystinuria and phenylketonuria, which are also associated with abnormal levels of amino acids.
Jee S.H.,Gachon University |
Kim J.W.,LabGenomics Co. |
Lee J.H.,LabGenomics Co. |
Yoon Y.S.,Gachon University
International Journal of Nanomedicine | Year: 2015
A glass platform with high sensitivity for sexually transmitted diseases microarray is described here. An amino-silane-based self-assembled monolayer was coated on the surface of a glass platform using a novel bubbling method. The optimized surface of the glass platform had highly uniform surface modifications using this method, as well as improved hybridization properties with capture probes in the DNA microarray. On the basis of these results, the improved glass platform serves as a highly reliable and optimal material for the DNA microarray. Moreover, in this study, we demonstrated that our glass platform, manufactured by utilizing the bubbling method, had higher uniformity, shorter processing time, lower background signal, and higher spot signal than the platforms manufactured by the general dipping method. The DNA microarray manufactured with a glass platform prepared using bubbling method can be used as a clinical diagnostic tool. © 2015 Jee et al.
Kim M.I.,Gachon University |
Cho D.,LabGenomics Co. |
Park H.G.,Korea Advanced Institute of Science and Technology
Journal of Nanoscience and Nanotechnology | Year: 2015
In this study, a microscale well-plate colorimetric assay for the multiplexed detection of glucose and cholesterol in clinical human blood samples has been developed. This system utilized one-pot nanocomposite entrapping Fe3O4 magnetic nanoparticles (MNPs) as peroxidase mimetics and glucose oxidase (GOx)/cholesterol oxidase (ChOx) in mesoporous silica to detect glucose and cholesterol in blood samples. The sensing mechanism involves the generation of H2O2 by the catalytic action of an immobilized oxidase on the target molecules in the sample. This subsequently activates the MNPs in the mesopores, thereby leading to the conversion of the substrate into a colored end product. This strategy is used to detect the target glucose or cholesterol molecules in the concentration range of 15-250 mg/dL. The response is highly linear and the lower detection limit is 7.5 mg/dL. The aforementioned colorimetric assay is extremely convenient, and it exhibits a high degree of linearity, precision, and reproducibility when employing real human blood samples. Therefore, this assay can be used in clinical practice for the multiplexed and reliable quantification of glucose and cholesterol. Copyright © 2015 American Scientific Publishers All rights reserved.
PubMed | Labgenomics Co., Korean University of Science and Technology and Korea Advanced Institute of Science and Technology
Type: | Journal: Biosensors & bioelectronics | Year: 2016
We herein describe a new mass spectrometry-based method for multiplex SNP genotyping by utilizing allele-specific ligation and strand displacement amplification (SDA) reaction. In this method, allele-specific ligation is first performed to discriminate base sequence variations at the SNP site within the PCR-amplified target DNA. The primary ligation probe is extended by a universal primer annealing site while the secondary ligation probe has base sequences as an overhang with a nicking enzyme recognition site and complementary mass marker sequence. The ligation probe pairs are ligated by DNA ligase only at specific allele in the target DNA and the resulting ligated product serves as a template to promote the SDA reaction using a universal primer. This process isothermally amplifies short DNA fragments, called mass markers, to be analyzed by mass spectrometry. By varying the sizes of the mass markers, we successfully demonstrated the multiplex SNP genotyping capability of this method by reliably identifying several BRCA mutations in a multiplex manner with mass spectrometry.
Korea Advanced Institute of Science, Technology and Labgenomics Co. | Date: 2011-11-29
A DNA chip for diagnosis of genitourinary infection, and in particular, a DNA chip for diagnosis of genitourinary infection on which oligonucleotide probes for detecting fourteen genitourinary infection pathogens are immobilized is provided. The DNA chip for diagnosis of genitourinary infections may accurately and rapidly analyze infections of fourteen genitourinary infections including multiple infections in various samples with high sensitivity, high specificity, and high reproducibility. Accordingly, the DNA chip may be used for diagnosis and treatment of genitourinary infections in primary health care institutions.
Labgenomics Co. | Date: 2010-05-20
Provided are a microorganism for use in quantification of homocysteine and methionine and a method of quantifying homocysteine and methionine in a sample by using the microorganism.