Parametric analysis of a novel semi-circular microfluidic CD-ELISA valve

Abstract

CD-ELISA uses the microfluidic ranking method and centrifugal force to control the testing solution as it flows into the reaction region. The most challenging part of CD-ELISA is controlling the flow process for different biological testing solutions, i.e. the controlling sequence for the microfluidic channel valves. The microfluidic channel valve is therefore the most important fluid channel structure for CD-ELISA. In this study, we propose a valve design suitable for a wide range rotational speeds which can be applied for mass production (molding). Together with supporting experiments, simulation based on two-phase flow theory is used in this study, and the feasibility of this novel valve design is confirmed. Influencing design factors for the microfluidic channel valves in CD-ELISA are investigated, including various shapes of the arc, distance d, radius r, the location of the center of the circle, and the contact angle. From both the experimental results and the simulated results, it is evident that the narrowest channel width and the contact angle are the primary factors influencing valve burst frequency. These can be used as the main controlling factors during the design.

Renewable and tuneable bio-LPG blends derived from amino acids

“…These plasmids are a modified pHal2-based plasmid [ 4 ] containing RFP with the T7-like promoter swapped for a modified pPorin-like constitutive promoter. The BglBrick series of vectors were obtained from Addgene ( https://www.addgene.org ) [ 40 ]. Gene synthesis was performed by GeneArt (ThermoFisher, Germany) or GenScript (USA).…”

Promoter engineering for microbial bio-alkane gas production

“…Individually sequenced clones were ranked according to their RFU, which is a measure of culture fluorescence intensity per unit cell density (see Figure 1 and Supplementary Table S3 ). Data were compared to those generated by IPTG-inducible RFP constructs, which differed by the promoter system utilized (T7-like MmP1 ( 26 ), pTrc or placUV5 ) and plasmid backbone (pHal2 ( 3 ) versus BglBrick vectors ( 25 ); see Supplementary Table S4 ).…”

“…Details of all the sequence-verified plasmids used in this study can be found in Supplementary Table S1 , and the sequences of the oligonucleotides used in cloning and mutagenesis in Supplementary Table S2 . The BglBrick series of vectors were obtained from Addgene ( 25 ). The DNA sequences and accession numbers of the constructs/plasmids used for data collection are found in the Supplementary data .…”

“…This construct (pHalT7P7-CvFAP G462V ) was modified further in three stages, beginning with the replacement of CvFAP G462V with RFP from the BioBrick vector pBbE1c-RFP ( 25 ) to generate pHalT7P7-RFP. This was followed by the elimination of the now obsolete T7-like promoter (pHal7-RFP-STag) and subsequent C-terminal S-Tag removal to generate a constitutive expression construct for RFP (pHal7-RFP).…”

“…A second control plasmid pHal7 was constructed by the elimination of the RFP gene from pHal7-RFP by PCR. Additional controls were two BioBrick vectors composed of RFP downstream of IPTG-inducible pTrc (pBbA1a) or placUV5 (pBbA5a) promoters ( 25 ). In each case, plasmid linearization and gene amplification steps were performed by PCR followed by In-Fusion cloning to ligate the constructs.…”