• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.2
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• pp.127-131
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• 2004

A low-cost, simple strip reader system using a linear movement mechanism of CD-ROM deck has been developed to characterize a lateral flow membrane-based immunochromatographic assay. The test strip reader was assembled by a CD-ROM deck and home-made optical head especially designed for immunoassays. The optical head for detecting reflected light from the test strip surface consists of green light-emitting diode, large area silicon photodiode, and anodized aluminum mounting block providing a slit structure for cutting light from the LED. The stepping motor of the deck was operated in the full step mode, whose distance of each reading point is about 0.15mm. The performance of the strip reader was tested by analysis of HBV(hepatitis B virus) antigen test kit. This strip reader can be useful for inexpensive, disposable, and membrane-based assays that provide visual evidence of the presence of an analyte in a liquid sample.

• Journal of Microbiology and Biotechnology
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• v.26 no.11
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• pp.1855-1862
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• 2016

Cronobacter sakazakii (C. sakazakii) is a foodborne pathogen, posing a high risk of disease to infants and immunocompromised individuals. In order to develop a quick, easy, and sensitive assay for detecting C. sakazakii, a rabbit anti-C. sakazakii immunoglobulin G (IgG) was developed using sonicated cell protein from C. sakazakii. The developed anti-C. sakazakii (IgG) was of good quality and purity, as well as species-specific. The developed rabbit anti-C. sakazakii IgG was attached to the surface of a sulforhodamine B-encapsulated liposome to form an immunoliposome. A test strip was then prepared by coating goat anti-rabbit IgG onto the control line and rabbit anti-C. sakazakii IgG onto the test line, respectively, of a plastic-backed nitrocellulose membrane. A purple color signal both on the test line and the control line indicated the presence of C. sakazakii in the sample, whereas purple color only on the control line indicated the absence of C. sakazakii in the sample. This immunochromatographic strip assay could produce results in 15 min with a limit of detection of $10^7CFU/ml$ in C. sakazakii culture. The immunochromatographic strip assay also showed very good specificity without cross-reactivity with other tested Cronobacter species. Based on these results, the developed immunochromatographic strip assay is efficient for the detection of C. sakazakii and has high potential for on-site detection.

• Korean Journal of Veterinary Research
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• v.45 no.2
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• pp.169-177
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• 2005

We developed the one-step strip based on an immunochromatographic (IC) assay for the rapid detection of Listeria spp. Genus-specific monoclonal antibody to flagella of L. monocytogenes was conjugated with 40 nm colloidal gold particles which were prepared in our laboratory. The specificity of the IC strip was tested with pure cultured bacteria. All strains of the genus of Listeria spp. yielded positive reactions and 12 strains of non-Listeria were negative, resulting in a specificity of 100%. L. monocytogenes was artificially inoculated in raw pork macerated with listeria enrichment broth. And then it was 10-fold diluted from $8.7{\times}10^6$ to 8.7 CFU/ml. L. monocytogenes could be detected at a minimum of $8.7{\times}10^5CFU/ml$ before enrichment, $8.7{\times}10^2CFU/ml$ after primary enrichment and 8.7 CFU/ml after secondary enrichment, respectively. These results indicated that the IC strip exhibited high specificity and sensitivity in the detection of Listeria spp.

• ALGAE
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• v.28 no.3
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• pp.289-296
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• 2013

For the quantitative detection of algal toxin, microcystin, a chemiluminescence immunochromatographic assay method was developed. The developed system consists of four parts, chemiluminescence assay strip (nitrocellulose membrane), horse radish peroxidase labeled microcystin monoclonal antibodies, chemiluminescence substrate (luminol and hydrogen peroxide), and luminometer. The performance of the chemiluminescence immunochromatographic assay system was compared with high performance liquid chromatography (HPLC) detection. The detection limit of chemiluminescence immunochromatographic assay system is several orders of magnitude lower than with HPLC. The chemiluminescence immunochromatography and HPLC results correlated very well with the correlation coefficient ($r^2$) of 0.979.

• Food Science and Biotechnology
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• v.17 no.3
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• pp.623-630
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• 2008

A non-instrumental immunochromatographic (ICG) strip-test and direct competitive enzyme-linked immunosorbent assay (DC-ELISA) for aflatoxin B1 (AFB1) determination were developed and optimized. The detection limits of ICG strip-test and DC-ELISA were 0.5 and 0.004 ng/mL, respectively, and these methods possessed a cross-reaction to aflatoxins. The results of spiked samples by both methods were coincided with the amount spiked AFB1 and the comparative analyses of 172 real samples by 2 immunoassays and high performance liquid chromatography (HPLC) showed a good agreement. Especially, the ICG strip-test is easier to perform and quicker, but less sensitivity than DC-ELISA. Both methods could analyze a high sample throughput with short time, but the sample throughput of ICG strip-test was better. Therefore, the ICG strip-test can be used as a simple, easy, non-instrumental, and fast screening technique for AFB1 determination.

• Bulletin of the Korean Chemical Society
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• v.32 no.1
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• pp.149-152
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• 2011

A new chemiluminescence immunochromatographic analysis system with high sensitivity and high reproducibility was developed for the determination of microcystins (MCs) in water. Horse radish peroxidase (HRP) labeled microcystin monoclonal antibody was used for the sensitive chemiluminescence detection. The chemiluminescence immunochromatographic analysis system was composed of microcystin LR (MCLR)-monoclonal antibody (mAb)-Horse Radish Peroxidase (HRP) conjugate, MCLR-BSA conjugate, luminol, hydrogen peroxide mixture solution, an immunochromatographic assay strip and luminometer. To detect the concentration of microcystins in water, we utilized one spot analysis of the strip instead of flow type analysis. We could detect the microcystins in water at a concentration as low as 9.45 pg/mL with the chemiluminescence (CL) detection.

• Korean Journal of Veterinary Research
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• v.45 no.2
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• pp.191-197
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• 2005

An immunochromatographic (IC) strip for the rapid detection of Salmonella spp. in the enriched sample was developed. Affinity purified Salmonella polyclonal antibody was conjugated with 40 nm colloidal gold particles which were prepared by citrate method in our laboratory. The antigen-antibody-gold complex was captured by Salmonella antibody attached to test line of nitrocellulose membrane during the capillary migration of sample. Specificity of the IC strip was calculated to be 100% (12/12) and sensitivity was 97.6% (41/42) in the test with pure cultured bacteria. Salmonella was artificially inoculated into raw pork macerated with enrichment broth. And then it was 10-fold diluted from $5.2{\times}10^{8}CFU/ml$ to 5.2 CFU/ml. The IC strip could detect $5.2{\times}10^{6}CFU/ml$ before enrichment. However, the lowest limit of detection was 5.2 CFU/ml after overnight incubation. The results indicated that the IC assay was a rapid, economical and simple method with high specificity and sensitivity for the detection of Salmonella spp. without using any equipment.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.273-273
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• 2013

Recently, Point-of-care (POC) testing microdevices enable to do the patient monitoring, drug screening, pathogen detection in the outside of hospital. Immunochromatographic strip (ICS) is one of the diagnostic technologies which are widely applied to POC detection. Relatively low cost, simplicity to use, easy interpretations of the diagnostic results and high stability under any circumstances are representative advantages of POC diagnosis. It would provide colorimetric results more conveniently, if the genetic analysis microsystem incorporates the ICS as a detector part. In this work, we develop a reverse transcriptase-polymerase chain reaction (RT-PCR) microfluidic device integrated with a ROSGENE strip for colorimetric influenza H1N1 virus detection. The integrated RT-PCR- ROSGENE device is consist of four functional units which are a pneumatic micropump for sample loading, 2 ${\mu}L$ volume RT-PCR chamber for target gene amplification, a resistance temperature detector (RTD) electrode for temperature control, and a ROSGENE strip for target gene detection. The device was fabricated by combining four layers: First wafer is for RTD microfabrication, the second wafer is for PCR chamber at the bottom and micropump channel on the top, the third is the monolithic PDMS, and the fourth is the manifold for micropump operation. The RT-PCR was performed with subtype specific forward and reverse primers which were labeled with Texas-red, serving as a fluorescent hapten. A biotin-dUTP was used to insert biotin moieties in the PCR amplicons, during the RT-PCR. The RT-PCR amplicons were loaded in the sample application area, and they were conjugated with Au NP-labeled hapten-antibody. The test band embedded with streptavidins captures the biotin labeled amplicons and we can see violet colorimetric signals if the target gene was amplified with the control line. The off-chip RT-PCR amplicons of the influenza H1N1 virus were analyzed with a ROSGENE strip in comparison with an agarose gel electrophoresis. The intensities of test line was proportional to the template quantity and the detection sensitivity of the strip was better than that of the agarose gel. The test band of the ROSGENE strip could be observed with only 10 copies of a RNA template by the naked eyes. For the on-chip RT-PCR-ROSGENE experiments, a RT-PCR cocktail was injected into the chamber from the inlet reservoir to the waste outlet by the micro-pump actuation. After filling without bubbles inside the chamber, a RT-PCR thermal cycling was executed for 2 hours with all the microvalves closed to isolate the PCR chamber. After thermal cycling, the RT-PCR product was delivered to the attached ROSGENE strip through the outlet reservoir. After dropping 40 ${\mu}L$ of an eluant buffer at the end of the strip, the violet test line was detected as a H1N1 virus indicator, while the negative experiment only revealed a control line and while the positive experiment a control and a test line was appeared.

• Journal of Veterinary Science
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• v.21 no.4
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• pp.68.1-68.8
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• 2020

A fluorescent microsphere-based immunochromatographic strip test (FICT) was developed for the rapid, sensitive, and quantitative detection of porcine reproductive and respiratory syndrome virus (PRRSV) antibodies at the pen-side. The assay was based on the formation of a sandwich immune-complex (anti-pig IgG-PRRSV antibodies-NSP7/N), which was validated by a comparison with IDEXX-ELISA using 3325 clinical specimens. The diagnostic specificity, sensitivity, and accuracy of FICT were 97.28, 93.41, and 94.95%, respectively. FICT showed a good correlation with the virus neutralization assay. Overall, a promising pen-side diagnostic tool was developed for the rapid and quantitative detection of PRRSV antibodies within 15 min.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2002.05a
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• pp.175-175
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• 2002