초록

Ⅳ. 연구개발결과
O-157 검출에 사용된 압타머의 DNA 정보는 다음과 같다.
5'-GGGTCTTCCTGGACTGTCGAAAATTCAGTATCGGGAGGTTACGTATTTGGTTTATAGATAGTAA-3’
실험에 사용된 O-157 항원은 서울시보건환경연구원으로부터 제공받아 실험 하였다(8.5 E+6). lipid layer 코팅을 한 입자를 사용한 실험과 lipid vesicle을 이용한 결과가 유사한 감도와 안정성을 보였다. 검출한계는 85 CFU/ml로 나타났다.

Abstract ▼

In this study, we report the use of “proximity” optical fibers (i.e. the fibers are in close contact but not touching the microfluidic device) to quantify increased light scattering due to nano particle immunoagglutination in a microfluidic device, with a detection limit lower (preferably at the lev

In this study, we report the use of “proximity” optical fibers (i.e. the fibers are in close contact but not touching the microfluidic device) to quantify increased light scattering due to nano particle immunoagglutination in a microfluidic device, with a detection limit lower (preferably at the level of single cell) than other traditional methods. We have previously demonstrated latex immunoagglutination assay in a microfluidic device by using ighly carboxylated magnetic particles with no surfactant.
Detection of O-157 in phosphate buffered saline (PBS) was demonstrated in a Y-channel microfluidic device through optical fiber monitoring of latex immunoagglutination. The nano particle immunoagglutination assay was performed for serially diluted E. coli solutions using 0.60-μm highly carboxylated magnetic particles conjugated with O-157 aptamer. Pre-treatments such as cell lysis or culturing to enhance the signal were not used. Proximity optical fibers around the view cell of the device were used to quantify the increase in 45° forward light scattering of the immunoagglutinated particles. In order to reduce false positive signals caused by antibodies binding to non-viable E. coli cells or free antigens in solution, target solutions were washed three times, and then the results were compared to non-washing treatments. The detection limit was found to be less than 10 cfu ml−1 (1 cfu per device) without PBS washing (thus detecting non-viable cells and free antigens), or less than 40 cfu ml−1 (4 cfu per device) with PBS washing (thus detecting viable E. coli cells only).