• Korean Chemical Engineering Research
• /
• v.56 no.1
• /
• pp.79-84
• /
• 2018

In the present study, we performed electroporation to deliver protein into microalgae using previously developed digital electroporation system. Green fluorescence protein was successfully delivered into a live microalgae cell nucleus without cell wall removal. By investigating the effects of applied voltage on the protein delivery efficiency, optimal electroporation electric field condition was found (960 V/cm). We also investigated the delivery of Yo-Pro-1 into cell to examine the size effects of delivered materials and found that there is little size effects on the optimal condition. Finally, the implications of the present results and future work are discussed.

• Clean Technology
• /
• v.21 no.2
• /
• pp.90-95
• /
• 2015

Digital microfluidic electroporation system was used for the transformation of microalgae and we have obtained higher transformation efficiency and viability than that of conventional method. Key parameters of electroporation such as pulse voltage, number, and duration time were systematically investigated for two different microalgal strains with and without cell wall. We have found that cell wall does not always have negative effects on the gene transformation of microalgae. Parallel processing of proposed digital microfluidic electroporation was demonstrated together with on chip culture of microalgae.

• Korean Chemical Engineering Research
• /
• v.58 no.3
• /
• pp.450-457
• /
• 2020

In the previous study, there was a big difference between the tendency of the delivery efficiency of Yo-Pro-1 and the expression efficiency of the CFP gene, but there was a problem that could not provide a clue to this problem. Therefore, this study aimed to present a clue to this problem by quantifying and comparing the delivery efficiency after labeling DNA using a fluorescent dye, which was one of the methods for quantifying biomolecules. As a fluorescent dye for labeling, Yo-Pro-1 was used, and the delivery efficiency of the fluorescent dye Yo-Pro-1 and the labeled DNA was compared. The delivery efficiency of Yo-Pro-1 and labeled DNA according to the voltage condition of the digital electroporation system was maximized at 96 V, and the delivery efficiency tended to decrease as the voltage increased further. In the comparison of the delivery efficiency of Yo-Pro-1 and labeled DNA according to the number of voltage application conditions, the delivery efficiency was maximized at the number of 8 voltage application times for both delivery materials, and the delivery efficiency tended to decrease as the number of voltage application increases further. Through the two results, it was confirmed that the delivery efficiency using Yo-Pro-1 in the digital electroporation system represents the delivery efficiency of the system well. In addition, through the results of this study, the difference between the tendency of the delivery efficiency of Yo-Pro-1 and the expression efficiency of the CFP gene shown in the preceding study was not the result of the difference in the delivery efficiency of the delivery material, but it can be predicted to be due to a problem with the expression process of the genetic material that had been delivered.

• Korean Chemical Engineering Research
• /
• v.57 no.5
• /
• pp.706-713
• /
• 2019

In this study, basic research was conducted to provide guidelines for selecting printers and materials suitable for each application case by analyzing 3D printing method and surface characteristics of materials suitable for microfluidic system. We have studied the surface characteristics according to the materials for the two typical printing methods: The most commonly used method of Fused Deposition Modeling (FDM) printing and the relatively high resolution method of Stereolithography (SLA) printing. The FDM prints exhibited hydrophilic properties before post - treatment, regardless of the material, but showed hydrophobic properties after post - treatment with acetone vapor. It was confirmed by the observation of surface roughness using SEM that the change of the contact angle was due to the removal of the surface structure by post-treatment. SLA prints exhibited hydrophilic properties compared to FDM prints, but they were experimentally confirmed to be capable of surface modification using hydrophobic coatings. It was confirmed that it is impossible to make a transparent specimen in the FDM method. However, sufficient transparency is secured in the case of the SLA method. It is also confirmed that the electroporation chip of the digital electroporation system based on the droplet contact charging phenomenon was fabricated by the SLA method and the direct application to the microfluidic system by demonstrating the electroporation successfully.