Automated and parallel microfluidic DNA extraction with integrated pneumatic microvalves/pumps and reusable open‐channel columns

Abstract

A novel microfluidic DNA extraction protocol based on integrated diaphragm microvalves/pumps and silica‐deposited open‐channel columns was developed specifically for automated and parallel DNA solid‐phase extraction (SPE). The method uses microfluidic chips with a sandwiched structure containing three layers, which are the upper fluidic layer with surface‐deposited silica on glass open channels as the extraction phase, the lower actuation layer with valve actuation channels on a glass wafer, and the middle poly(dimethylsiloxane) (PDMS) membrane for reversible bonding of the two glass substrates. These two glass substrates can be reused after thoroughly cleaning and the PDMS membrane can be replaced conveniently, which could effectively decrease the time and cost of chip manufacturing. The normally closed microvalves/pumps were used to automatically control all processes of the on‐chip DNA SPE without cross‐contamination and leakage, enabling the processing of multiple samples in parallel without changing the microvalve control module. Using the microchip device with integrated microvalves/pumps, automated, programmable, and simultaneous λ‐DNA extractions from different samples could be attained, even from complex solutions such as human blood, and the silica‐deposited open‐channel columns could be reused stably and reliably. Results have demonstrated that most of the eluted λ‐DNA was recovered in the second 2 µL of elution buffer with high‐purity suitable for successful polymerase chain reaction amplification, making it possible for further integration into microfluidic devices for fully functional and high‐throughput genetic analysis.

Automated cellular stimulation with integrated pneumatic valves and fluidic capacitors

“…Integrated pneumatic valves are widely used in flow gating and can be readily automated using computerassisted programming. 19,[24][25][26] This automation in addition to reducing the chances of contamination can also lead to more complex fluidic systems without sacrificing the ease of vacuum-based fluid control.…”

Actuation for flexible and stretchable microdevices

“…[203][204][205][206][207][208][209][210][211][212][213] Pneumatically actuated on-chip microvalves and micropumps are essential for efficient and accurate fluid delivery in biomedical analyses. 51,61 Zhong et al 214 developed diaphragm microvalves and micropumps for automated and parallel DNA solid-phase extraction from various biological samples to eliminate cross-contamination and leakages. In addition, Lee et al 51,52,59,60,62,200,215 have developed microfluidic platforms for automated, synchronous, and multiple sample analysis for various biological tests utilising on-chip microvalves and micropumps.…”