• Journal of Biosystems Engineering
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• 제38권4호
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• pp.335-340
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• 2013

Purpose: This study was performed to develop a lateral flow strip sensor for the detection of pathogenic Escherichia coli O157:H7 in various samples. Also, feasibility of using an image analysis method to improve the interpretation of the strip sensor was evaluated. Methods: The lateral flow strip sensor has been fabricated based on nitrocellulose lateral-flow membrane. Colloidal gold and E. coli O157:H7 antibodies were used as a tag and a receptor, respectively. Manually spotted E. coli O157:H7 antibody and anti-mouse antibody on nitrocellulose membrane were used as test and control dots, respectively. Feasibility of the lateral flow strip sensor to detect E. coli O157:H7 were evaluated with serially diluted E. coli O157:H7 cells in PBS or food samples. Test results of the lateral flow strip sensor were measured with an image analysis method. Results: The intensity of the test dot started to increase with higher concentration of the cells were introduced. The sensitivities of the sensor were both $10^4$ CFU/mL Escherichia coli O157:H7 spiked in PBS and in chicken meat extract, respectively. Conclusions: The lateral flow strip sensor and image analysis method could detect E. coli O157:H7 in 20 min, which is significantly quicker than conventional plate counting method.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권2호
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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 Biosystems Engineering
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• 제40권3호
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• pp.277-283
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• 2015

Background: Foodborne disease outbreaks from various food sources are a major health concern worldwide. Current methods for detection of foodborne pathogens are both expensive and time-consuming. Purpose: This review aims to present the current information available on the use of lateral flow test strips to detect pathogens in food products to enhance food safety. Results: Frequent foodborne disease outbreaks from various food sources have increased the need for rapid and easy methods for routine analysis of foodborne pathogens. Present detection methods for foodborne pathogens require expensive instruments, experts, and long time for sample analysis. Lateral flow test strips have drawn attention in recent years because of their ability to detect analytes quickly and easily. This review focuses on the principle of the lateral flow test, the various formats of lateral flow test strips, recognition elements, labeling tags, and reading instruments. In addition, this review also discusses the future prospects for the lateral flow test strips.

• 농업과학연구
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• 제46권3호
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• pp.549-557
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• 2019

Staphylococcal enterotoxin is a very common cause of food poisoning. Conventional detection methods for the toxin including enzyme-linked immunosorbent assays (ELISAs), chemiluminescence (ECL), and polymerase chain reaction (PCR) assays require a lot of time, efforts, and expert technicians. Lateral flow strip kits have shown great potential for the rapid detection of foodborne pathogens. The lateral flow strip kit is widely used in clinical settings because it is easy to use, fast, and cost effective. A typical lateral flow strip kit uses colloidal gold to generate a visual signal. However, the lateral flow strip kit based on colloidal gold has limited sensitivity to fulfill food safety regulation requirements. This study was performed to develop a rapid test kit for pathogenic staphylococcal enterotoxin B (SEB) in food samples. The rapid detection kit was fabricated based on a nitrocellulose lateral-flow strip. Cellulose nano beads and SEB antibodies were used as the tag and receptor, respectively, to improve the detection performance. Manually spotted SEB antibody and anti-rabbit antibody on the surface of the nitrocellulose membrane were used as test and control spots, respectively. The feasibility of the rapid test kit to detect SEB in samples was evaluated. The sensitivity of the kit was 10 ng/mL SEB spiked in PBS. Additionally, the rapid test kit could detect 1 ng/mL of SEB in chicken meat extract.

• Applied Biological Chemistry
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• 제48권1호
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• pp.77-81
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• 2005

GM 콩으로 제조된 두부와 비지 등 콩 가공제품들의 효율적인 모니터링을 위하여 GM 콩이 0%, 1%, 3%, 5%, 100% 함유된 두부와 비지를 제조하여 이들의 삽입유전자인 5-enolpyruvylshikimate-3-phosphate synthase(epsps)를 검출하기 위한 PCR 방법과 EPSPS 발현 단백질 검출을 위한 western blotting과 lateral flow strip을 사용하여 검출 감도를 비교하였다. PCR 결과 산물의 크기가 큰 600 bp의 증폭에서 두부의 경우에는 100% GM으로 제조된 두부에서만 확인이 가능하였고, 비지에서는 5%, 100%에서 확인이 되었다. 크기가 작은 123 bp가 생성되는 실험에서는 0%를 제외한 모든 두부와 비지에서 검출되었다. Western blot 결과는 100% 두부, 비지에서만 검출이 되었고, lateral flow strip test에서는 100% 비지에서만 검출되었다. 이러한 결과로부터 GM 콩 가공식품 검출은 면역학적 방법보다는 PCR이 더 높은 민감도가 나타내는 것을 확인하였고, 또한 가공식품에서 효율적인 GMO 검출을 위해서는 100 bp 정도의 작은 크기의 PCR 산물을 이용해야 민감한 검출 결과를 보여주는 것을 확인하였다.

• Journal of Mechanical Science and Technology
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• 제17권3호
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• pp.429-439
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• 2003

Counter-current two-phase flows of air- water in narrow rectangular channels with offset strip fins have been experimentally investigated in a 760 mm long and 100 mm wide test section with 3.0 and 5.0 mm gap widths. The two-phase flow regime, channel-average void fractions and two-phase pressure gradients were studied. Flow regime transition occurred at lower superficial velocities of air than in the channels without fins. In the bubbly and slug flow regimes, elongated bubbles rose along the subchannel formed by fins without lateral movement. The critical void fraction for the bubbly-to-slug transition was about 0.14 for the 3 mm gap channel and 0.2 for the 5 mm gap channel. respectively. Channel-average void fractions in the channels with fins were almost the same as those in the channels without fins. Void fractions increased as the gap width increased, especially at high superficial velocity of air. The presence of fins enhanced the two-phase distribution parameter significantly in the slug flow, where the effect of gap width was almost negligible. Superficial velocity of air dominated the two-phase pressure gradients. Liquid superficial velocity and channel gap width has only a minor effect on the pressure gradients.

• Journal of Biosystems Engineering
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• 제36권2호
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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.

• 농업과학연구
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• 제40권2호
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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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• 제51권10호
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• pp.1071-1076
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• 2008

목적: RSV 호흡기 바이러스 감염은 해마다 영유아에서 심한 호흡기 질환의 중요한 원인이 되고 있다. 이에 따라 최근 검사 방법이 간편하고 결과를 빨리 알 수 있는 면역 크로마토그래피법이 신속 항원 검사법으로서 소개되어 그 정확성과 임상에서의 유용성이 많이 연구되고 있으나 국내에서는 연구례가 드문 실정이다. 이에 저자들은 이 검사법의 정확성과 유용성을 평가하여 실질적인 검사법으로 정착시키고자 하였다. 방법: 2007년 4월부터 2008년 3월까지 발열, 기침, 천명, 호흡곤란, 빈호흡 등의 증상으로 외래 내원 및 입원치료를 받은 112명의 환아를 대상으로 비인두 가검물을 채취하여 RSV Respi-Strip과 효소 면역 측정법, RT-PCR(ASTEC)을 동시에 시행하였다. RT-PCR을 표준으로 하여 RespiStrip 과 EIA의 결과를 비교 분석하여 정확성과 유용성을 평가하였다. 결 과: RSV RespiStrip, RT-PCR, EIA에 양성을 보인 환아는 각각 42명, 45명, 39명 이었다. RespiStrip는 RT-PCR 검사법에 대하여 민감도 88%, 특이도 94%, 양성 예측도 90%, 음성 예측도는 92% 였으며 위양성률과 위음성률 그리고 일치도가 각각 5.9%, 11%, 83% 로 나왔다. EIA는 RT-PCR 검사법에 대하여 민감도 84%, 특이도 94%, 양성 예측도 90%, 음성 예측도 90%, 일치도 79% 로 나왔다. 결론: 신속 항원 검사가 비교적 민감도가 높으므로 RSV 감염의 선별 검사로서 적합하다고 생각한다. 외래 진료실에서 빠르고 경제적이며 간편하게 검사하여 조기에 적절한 치료를 함으로써 합병증을 예방할 수 있고 아울러 불필요한 항생제의 사용을 줄일 수 있다. 앞으로 이러한 신속검사가 실제 임상에서 많이 적용되리라 기대된다.

• 공업화학
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• 제30권4호
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• pp.429-434
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• 2019

본 논문에서는 수용성의 CdSe/ZnS 양자점을 합성하고 이에 항체기능성을 도입하여 lateral flow immunoassay (LFIA) 플랫폼에 융합하여 폐암 질병진단에 활용 가능한 단백질 바이오마커[예: 인간 혈청 아밀로이드 A-1 (hSAA1)]의 농도 분석에 적용하고자 한다. 면역분석법 센서 스트립은 니트로셀룰로오즈 막에 테스트라인과 대조라인으로 각각 항hSAA1 단일클론항체(10G1)(anti-hSAA1)와 항chicken IgY (anti-chicken IgY)를 스프레이하여 제작하였다. 이와 함께, 유기상에서 합성된 CdSe/ZnS 양자점은 카르복실기로 변형된 알케인티올기를 이용한 리간드 교환방법으로 수용성으로 전환하였으며, 이에 타겟 단백질인 hSAA1에 특이적으로 결합 가능한 항체인 항hSAA1 단일클론항체(14F8)로 컨쥬게이션하여 형광검출용 입자[QDs-anti hSAA1 (14F8)]로 사용하였다. 제작된 LFIA 스트립 위에 순차적으로 다른 농도의 hSAA1과 QDs-anti hSAA1 (14F8)의 복합체를 흘려주면, 테스트라인에 anti hSAA1 (10G1)/hSAA1/QDs-anti hSAA1 (14F8) 샌드위치 복합체가 형성되어 양자점에 의한 발광신호가 검출됨을 측정하였다. 최적화된 측방흐름이 가능한 완충용액 조건에서 100 nM 농도의 hSAA1 단백질의 유무를 5 min 안에 눈으로 확인 가능하였다.