Microfluidic Array Chip for Parallel Detection of Waterborne Bacteria

Abstract

The polymerase chain reaction (PCR) is a robust technique used to make multiple copies of a segment of DNA. However, the available PCR platforms require elaborate and time-consuming operations or costly instruments, hindering their application. Herein, we introduce a sandwiched glass–polydimethylsiloxane (PDMS)–glass microchip containing an array of reactors for the real-time PCR-based detection of multiple waterborne bacteria. The PCR solution was loaded into the array of reactors in a single step utilising capillary filling, eliminating the need for pumps, valves, and liquid handling instruments. Issues of generating and trapping bubbles during the loading chip step were addressed by creating smooth internal reactor surfaces. Triton X-100 was used to enhance PCR compatibility in the chip by minimising the nonspecific adsorption of enzymes. A custom-made real-time PCR instrument was also fabricated to provide thermal cycling to the array chip. The microfluidic device was successfully demonstrated for microbial faecal source tracking (MST) in water.

Core-Shell Beads as Microreactors for Phylogrouping of E. coli Strains

“…Our results show that 5 min blue light illumination did not cause severe effect on photobleaching of the PCR products due to the short exposure time and the protective shell. However, our previous studies [28,44] indicated that constant exposure on the sample during thermal cycling over a long period of time can cause photobleaching of amplicons. This issue was solved by non-continuous illumination on the beads during thermal cycling.…”

“…Microfluidics was successfully utilised for nucleic acid amplification [28]. Lab-on-a-chip systems attracted a great deal of attention from the research community and the industry due to their advantages such as real-time analysis, miniaturization, portability, and high throughput [29].…”

Biomolecular Monitoring Tool Based on Lab-on-Chip for Virus Detection

“…A LoC for DNA amplification needs to include multiple integrated components such as thermalization and temperature measurement to provide the temperature cycles, the detection element to follow the DNA amplification, and the fluidic handling device, where the amplification reaction occurs [7,8]. Reports about the development of LoC-PCR systems show different techniques for providing temperature cycles, including commercially available external heaters, heaters integrated with the fluidic handling device made of thin metallic layers and noncontact heaters based on hot-air and IR-based heating [9,10]. Noncontact heaters are enabled to carry out up to 40 PCR cycles in 370 s. For the cooling phase, these optical systems often employ air cooling through a fan or only air contact in an open system (this latter leading to PCR contamination problems); moreover, they require cumbersome setups that hinder their integration.…”

Editorial for the Special Issue of 10th Anniversary of Micromachines

“…A total of 52 papers, including 42 original research articles, 9 review articles, and 1 brief report, are published in this Special Issue. A total of 14 out of the 52 papers in the Special Issue are selected as feature papers [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ].…”

“…Their findings would lead to novel solutions against bacterial fouling by reducing the extent of cavity flow. Valentina Palacio-Castañeda et al developed a tumor-on-a-chip model to investigate the metabolic switching of tumor cells under hypoxic conditions [ 2 ]. They discovered that a rapid metabolic switch of tumor cells under hypoxic conditions led to increased glycolysis.…”