• Journal of Sensor Science and Technology
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• v.20 no.6
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• pp.400-405
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• 2011

This study introduced the development of a strip type disposable enzyme-linked immunosensor platform for the detection of IgG. Strips of the strip sensor were fabricated by using commercial nitrocellulose filter membranes and a housing holder for the strips was manufactured by using a standard injection molding process for a plastic material. An IgG-urease conjugate was prepared and used for the competitive immune-binding with sample IgG. From the enzymatic reaction between the conjugated urease and urea added, ammonia was generated and caused a localized alkaline pH change on the immobilized antibody band which was coated onto the sensor strips. This pH increase subsequently caused a color change of the antibody band in the presence of a pH indicator, phenol red. Used in conjunction with a competitive immunoassay format, the intensity of the color produced is directly linked with the concentration of target analyte, IgG, and specific measurement of IgG in a lateral flow immunoassay format was achieved over the range 100 ppb to 2000 ppb IgG.

• Applied Chemistry for Engineering
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• v.30 no.4
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• pp.429-434
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• 2019

A lateral flow immunoassay platform utilizing antibody functionalized water soluble CdSe/ZnS semiconductor quantum dots (QDs) was developed for the analysis of human serum amyloid A-1 (hSAA1) in a buffer solution. hSAA1 was chosen as a target protein because it is regarded as a potential biomarker associated with early diagnosis and prognosis in patients of lung cancer. The immunoassay strip on a nitrocellulose membrane was fabricated by spraying two lines composed of a test line with a monoclonal antibody against hSAA1 (10G1) (anti hSAA1) and a control line of anti-chicken IgY. While the CdSe/ZnS QDs synthesized in an organic phase were transferred to a water phase by ligand exchange using carboxylic acid modified alkane thiol. The QDs was then conjugated to monoclonal antibody against hSAA1 (14F8) [anti hSAA1 (14F8)] and used as a fluorescent detection probe. The sequential lateral flow of hSAA1 in different concentration and QDs-anti hSAA1 (14F8) complex allowed to form the surface sandwich complex of anti hSAA1 (10G1)/hSAA1/QD-anti hSAA1 (14F8), which was then analyzed using fluorescence microscope. A 100 nM concentration of hSAA1 protein can be detected by naked eyes under an optimized lateral flow buffer condition with a sensing time of 5 mins.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.1B
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• pp.73-81
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• 2009

This paper presents a numerical investigation of the impact of the secondary currents on solute transport in open-channel flows. The RANS model with Reynolds stress model is used for flow modeling, and the GGDH(generalized gradient diffusion hypothesis) model is used to close the scalar transport equation. Using the developed model, the impact of secondary currents on solute transport in open channel flows over smooth-rough strip is investigated. Through numerical experiments, the secondary currents are found to affect the solute spreading, leading a movement of the position of the peak concentration and a skewed distribution of solute concentration. Due to the lateral flow of secondary currents near the free surface, the concentration at the rough strip is found to be larger than that at the smooth strip bed. The solute at the rough strip is more rapidly transported than smooth bed. A magnitude analysis of the solute transport rate in scalar transport equation is also carried out to investigate the effect of secondary currents and scalar flux on the concentration distribution.

• Journal of Biosystems Engineering
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• v.36 no.2
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• pp.140-146
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• 2011

This study was performed to develop a rapid test kit for pathogenic Salmonella in various samples. The rapid detection kit has been fabricated based on nitrocellulose lateral-flow strip. Colloidal gold and biotin conjugated Salmonella antibodies were used as a tag and a receptor, respectively. Manually spotted Salmonella antibody and Neutravidin on nitrocellulose membrane were used as test and control lines, respectively. Feasibility of the rapid kit to detect Salmonella typhimurium in samples were evaluated. The intensity of the color of the test line started to increase with the samples in which higher concentration of the cells were contained. The sensitivity of the sensor was $10^6$ cfu/mL Salmonella spiked in PBS. Also, the rapid test kit could detect $10^6$ cfu/mL of Salmonella in chicken meat extract.

• Korean Journal of Agricultural Science
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• v.40 no.2
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• pp.139-146
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• 2013

This study was performed to develop a rapid test kit for pathogenic Staphylococcus in various samples. The rapid detection kit has been fabricated based on nitrocellulose lateral-flow strip. Colloidal gold and Staphylococcus antibodies were used as a tag and a receptor, respectively. Manually spotted Staphylococcus antibody and anti-mouse antibody on the surface of nitrocellulose membrane were used as test and control lines, respectively. Feasibility of the rapid kit to detect Staphylococcus aureus in samples were evaluated. The intensity of the color of the test line started to increase with the samples in which higher concentration of the cells were contained. The sensitivity of the sensor was $10^6$ cfu/mL Staphylococcus spiked in PBS. Also, the rapid test kit could detect $10^5$ cfu/mL of Staphylococcus in chicken meat extract.

• Clinical and Experimental Pediatrics
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• v.51 no.10
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• pp.1071-1076
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• 2008

Purpose : Respiratory syncytial virus (RSV) is the most frequent cause of lower respiratory infections in infants and young children. Early detection allows quarantining of infected inpatients to prevent nosocomial transmission and to choose a treatment. To achieve rapid reporting, to facilitate prompt antiviral therapy, and to avoid unnecessary use of antibiotics, an easy, rapid diagnostic method for RSV is needed. We evaluated a lateral flow immunochromatography (RSV Respi-Strip test) and EIA (Enzyme immuno assay) compared to RT-PCR. Methods : From April 2007 to March 2008, 112 consecutive respiratory specimens (nasopharyngeal aspirates, throat swabs, tracheal aspirates, sputum) from patients who were suffering from the clinical signs and symptoms of respiratory tract infection were enrolled in Busan. A total of 112 patients were tested with RSV Respi-Strip (Corio-BioConcept, Belgium), EIA, and RT-PCR at the same time. Results : Of the 112 specimens tested, the number of children who showed positive results at RT-PCR and Respi-Strip were 45 and 42, respectively. The Respi-Strip rapid antigen test had a sensitivity of 88% and a specificity of 94%. The positive and negative predictive values were 90% and 92%, respectively. The agreement was 83%. Conclusion : In our study, the rapid antigen test had as much sensitivity as any method for detection of RSV. The test has many advantages such as easy performance, simple interpretation, and rapid results. If the rapid antigen test is widely applied in the clinical setting, the may be useful for diagnostic and epidemiological studies of RSV infection.

• Transactions of Materials Processing
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• v.23 no.7
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• pp.425-430
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• 2014

The aim of the current study was to predict the plastic deformation behavior of a heated slab during hot rough rolling. FE-simulations were performed to investigate the metal flow and to locate the position of surface material from the slab through the rough rolling and onto the strip, using a material point tracking technique. In addition, experimental hot rolling trials were conducted where artificial defects were impressed onto a heated slab in order to validate the FE-simulation results. The simulated results show the same tendency of deformation behavior as the experimental measurements. The movement of slab defects from the side surface towards the strip center is directly linked to the extent of lateral spread during the rolling.

• Korean Journal of Microbiology
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• v.39 no.2
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• pp.114-117
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• 2003

In molecular biology, it is necessary to develop an easy and rapid method to identify a specific DNA sequence. Though Southern and Northern blot techniques have been used widely for the analysis of gene structure and function, those methods are inconvenient in the points that we need to control incubation temperature, time, and other parameters to get the final result. In this study, we report a new method for the rapid analysis of specific DNA sequence with the modification of an immunochromatographic method. The lateral flow DNA analysis strip is composed of a sample pad, a nitrocellulose membrane for the separation and propagation of analytes, and an absorption pad for the generation of capillary action. Capture DNA was immobilized on the membrane by UV cross-linking and target DNA was labeled with Cy-5 for signaling. The samples containing target DNA were applied onto the sample pad, incubated for 15 min for separation, and scanned with a GSI fluorescence scanner. Though the hybridization reaction occurs in a short time without any washing steps, there appears to be little cross hybridization between the different sequences. The result showed a possibility that the new method can be used for the rapid identification of specific DNA sequence among the samples.

• IMMUNE NETWORK
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• v.21 no.1
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• pp.11.1-11.10
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• 2021

Coronavirus causes an infectious disease in various species and crosses the species barriers leading to the outbreak of zoonotic diseases. Due to the respiratory diseases are mainly caused in humans and viruses are replicated and excreted through the respiratory tract, the nasal fluid and sputum are mainly used for diagnosis. Early diagnosis of coronavirus plays an important role in preventing its spread and is essential for quarantine policies. For rapid decision and prompt triage of infected host, the immunochromatographic assay (ICA) has been widely used for point of care testing. However, when the ICA is applied to an expectorated sputum in which antigens are present, the viscosity of sputum interferes with the migration of the antigens on the test strip. To overcome this limitation, it is necessary to use a mucolytic agent without affecting the antigens. In this study, we combined known mucolytic agents to lower the viscosity of sputum and applied that to alpha and beta coronavirus, porcine epidemic diarrhea virus (PEDV) and Middle East respiratory syndrome coronavirus (MERS-CoV), respectively, spiked in sputum to find optimal pretreatment conditions. The pretreatment method using tris(2-carboxyethyl)phosphine (TCEP) and BSA was suitable for ICA diagnosis of sputum samples spiked with PEDV and MERS-CoV. This sensitive assay for the detection of coronavirus in sputum provides an useful information for the diagnosis of pathogen in low respiratory tract.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.677-682
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• 2004

Debates on safety of genetically modified (GM) crops have led to mandatory-labeling legislation of GM foods in many countries including Korea. Effects of heat, pressure, and acid treatments on degradation of DNAs or proteins in GM soybean at levels below detection limits of qualitative PCR and lateral flow strip test (LFST) methods were examined. Results showed that genomic DNAs and proteins were degraded into fragment sizes no longer possible for detection of inserted gene depending on thermal, or thermal and pressure treatment period. Detectaability of LFST for toasted meal increased in weakly treated soybean. DNA and protein detection methods were barely effective for detection of GM ingredient after $121^{\circ}C$ and 1.5 atmospheric treatment for 20 min. These results will be useful in determining GM labeling requirements of processed foods.