MICROBEAD-BASED LAB-ON-A-CHIP FOR PATHOGEN DNA DETECTION
Dongwoo Nam, Seunghyun Kwon, Wonhwi Na, Daeho Jang, Sehyun Shin
Korea University, South Korea
As there are numerous viruses spreading rapidly around the world, the number of corresponding casualties and damages has been increased. Thus, an accurate and rapid diagnosis of pathogens DNA is crucial for protecting ourselves from the threats and developing the therapy. One of the most diagnostic approaches is Polymerase Chain Reaction (PCR) ; widely used for molecular diagnostic assays for detecting nucleic acid (DNA, RNA) of infectious disease. Although it performs high sensitivity and specificity, PCR-based systems require certain equipment and educated analysts that are too expensive for resource-limited environment in developing countries, and the systems’ procedure time generally takes too long.
Thus, we developed a microbead based Lab-on-achip that can detect several pathogens at once with the small amount of sample. This system let us to detect pathogens with naked eyes using rolling circle amplification (RCA) in room temperature. What’s more, it can perform POCT even in developing country without any preinstalled equipment. This is a way to detect DNA by inducing hydrogel based on RCA on the microbead surface while a sample fluxing in a tube filled with majority of microbeads. Once the microbeads are densely set in high concentration, the sensitivity increases as the reacting surface of RCA dramatically grows and the surface area increases correspondingly. Also, it is able to relatively quantitate target material’s concentration by applying a method of measuring the sample’s traveled distance until the gap is completely blocked depending on the amount of product formed based on the reaction of RCA. In addition, it can detect more than three pathogens at once in units of fM on the chip.