Since microdroplets are able to be generated rapidly in large amount and each droplet can be well controlled as an independent micro-cultivator, droplet microfluidic technology can be potentially used in the culture of microorganisms, and provide the microbial culture with high throughput manner. But its application mostly stays in the laboratory-level building and using for scientific research, and the wide use of droplet microfluidics in microbial technology has been limited by the key problems that the operation for microdroplets needs high technical requirements with wide affecting factors and the difficulties in integration of automatic microdroplet instrumentation. In this study, by realizing and integrating the complicated operations of droplet generation, cultivation, detection, splitting, fusion and sorting, we design a miniaturized, fully automated and high-throughput microbial microdroplet culture system (MMC). The MMC can be widely used in microbial growth curve test, laboratory adaptive evolution, single factor and multi-level analysis of microbial culture, metabolite detection and so on, and provide a powerful instrument platform for customized microbial evolution and screening aiming at efficient strain engineering.
Industrial Development ; Microfluidics

Paper-based analytical devices are fluidic chips fabricated with extremely inexpensive materials, namely paper, thereby allowing their use as a zero-cost analytical device in third-world countries that lack access to expensive diagnostic infrastructures. The aim of this review is to discuss: (1) microfluidic paper-based analytical devices (microPADs) for quantitative analysis, (2) fabrication of two- or three-dimensional microPADs, (3) analytical methods of microPADs, and (4) our opinions regarding the future applications of microPADs for quantitative urinalysis.
Developing Countries ; Methods ; Microfluidics ; Urinalysis*

Microalgae are a group of photosynthetic microorganisms, which have the general characteristics of plants such as photosynthesis, and some species have the ability of movement which resembles animals. Recently, it was reported that microalgae cells can be engineered to precisely deliver medicine-particles and other goods in microfluidic chips. These studies showed great application potential in biomedical treatment and pharmacodynamic analysis, which have become one of the current research hotspots. However, these developments have been rarely reviewed. Here, we summarized the advances in manageable movement exemplified by a model microalgae Chlamydomonas reinhardtii based on its characteristics of chemotaxis, phototaxis, and magnetotaxis. The bottlenecks and prospects in the application of microalgae-based tactic movement were also discussed. This review might be useful for rational design and modification of microalgal manageable movement to achieve targeted transport in medical and other fields.
Chlamydomonas reinhardtii ; Microalgae ; Microfluidics ; Photosynthesis

We developed a high-efficiency microfluidic chip for extracting exosomes from human plasma. We collected peripheral blood from normal human, designed and fabricated a microfluidic chip based on nanoporous membrane and agarose gel electrophoresis to isolate exosomes. The extracted exosomes were characterized by transmission electron microscopy, nanosight and Western blotting, the morphology, concentration and particle size of exosomes were identified and analyzed. Meanwhile, we used ultracentrifugation and microfluidic chip to isolate exosomes separately. The particle size and concentration of the exosomes extracted by two methods were compared and analyzed, and their respective extraction efficiency was discussed. Finally, the expression level of miRNA-21 in exosomes was analyzed by RT-PCR. The microfluidic chip isolated (in 1 hour) high-purity exosomes with size ranging from 30-200 nm directly from human plasma, allowing downstream exosomal miRNA analysis. By comparing with ultracentrifugation, the isolation yield of microfluidic chip was 3.80 times higher than ultracentrifugation when the volume of plasma sample less than 100 μL. The optimized parameters for exosome isolation by gel electrophoresis microfluidic chip were: voltage: 100 V; concentration of agarose gel: 1.0%; flow rate of injection pump: 0.1 mL/h. The gel electrophoresis microfluidic chips could rapidly and efficiently isolate the exosomes, showing great potential in the research of exosomes and cancer biomarkers.
Exosomes ; Humans ; MicroRNAs/genetics* ; Microfluidics ; Plasma ; Ultracentrifugation

In recent 10 years, microfluidic technology has developed rapidly. Hence the speed of analysis can be upgraded, the performance be improved and the consumption of sample and reagent be reduced. In this review, we introduce the design, fabrication and application of microfluidic immunoassay chip.
Humans ; Immunoassay ; methods ; Microfluidic Analytical Techniques ; trends ; Microfluidics ; trends

Microfluidics technology may be an effective method to solve some problems in cryopreservation. This review presents the research progress of microfluidics technology in the field of cell membrane transport properties, cryoprotectant addition and washout and the vitrification for cryopreservation of biological materials. Existing problems of microfluidics technology in the application of cryopreservation are summarized and future research directions are indicated as well.
Cell Membrane ; Cryopreservation ; Cryoprotective Agents ; Membrane Transport Proteins ; Microfluidics

Recently, the droplet microfluidic system attracts interests due to its high throughput and low cost to detect and screen. The picoliter micro-droplets from droplet microfluidics are uniform with respect to the size and shape, and could be used as monodispensed micro-reactors for encapsulation and detection of single cell or its metabolites. Therefore, it is indispensable to characterize micro-droplet and its application from droplet microfluidic system. We first constructed the custom-designed droplet microfluidic system for generating micro-droplets, and then used the micro-droplets to encapsulate important amino acids such as glutamic acid, phenylalanine, tryptophan or tyrosine to test the droplets' properties, including the stability, diffusivity and bio-compatibility for investigating its application for amino acid detection and sorting. The custom-designed droplet microfluidic system could generate the uniformed micro-droplets with a controllable size between 20 to 50 microm. The micro-droplets could be stable for more than 20 h without cross-contamination or fusion each other. The throughput of detection and sorting of the system is about 600 micro-droplets per minute. This study provides a high-throughput platform for the analysis and screening of amino acid-producing microorganisms.
Amino Acids ; isolation & purification ; Microfluidic Analytical Techniques ; Microfluidics ; instrumentation

In recent years, molecular diagnostics has been the most promising branch of
Humans ; Microfluidics ; Molecular Diagnostic Techniques/instrumentation* ; Pathology, Molecular/instrumentation*

A high throughput measurement method of human red blood cells (RBCs) deformability combined with optical tweezers technology and the microfluidic chip was proposed to accurately characterize the deformability of RBCs statistically. Firstly, the effective stretching deformation of RBCs was realized by the interaction of photo-trapping force and fluid viscous resistance. Secondly, the characteristic parameters before and after the deformation of the single cell were extracted through the image processing method to obtain the deformation index of area and circumference. Finally, statistical analysis was performed, and the average deformation index parameters (
Erythrocyte Deformability ; Erythrocytes ; Humans ; Microfluidics ; Optical Tweezers ; Viscosity

BACKGROUND: Whole blood viscosity (WBV) refers to the internal resistance that occurs when blood flows through blood vessels. WBV is known to be related to many diseases including cardiovascular and neurovascular diseases. We have investigated the analytical performance and established reference intervals for a newly developed microfluidic viscometer, Viscore-300 (NanoBiz, Korea), used for the measurement of WBV. METHODS: We performed a precision test of 240 measurements over 20 days using three control materials. For evaluation of repeatability, a total of 60 WBV measurements were made in 3 whole blood samples 20 times a day. A total of 100 whole blood samples were used to evaluate the accuracy of the Viscore-300 in comparison to a rotating viscometer, DV3T (Brookfield, USA), in accordance with the the Clinical and Laboratory Standards Institute's guidelines. To establish the reference intervals, 122 healthy individuals were enrolled in this study. RESULTS: The precision and repeatability results showed that the CV was less than 5% for three samples and two shear rates. In the accuracy test, the mean differences between two viscometers were 0.09 cP (0.9%) and −0.07 cP (−1.4%) at shear rates of 10 s−1 and 300 s−1, respectively. The reference intervals of WBV for men were 6.88–13.52 cP at 10 s−1 and 4.32–6.43 cP at 300 s−1; those of women were 5.74–13.29 cP at 10 s−1 and 3.60–6.12 cP at 300 s−1. CONCLUSIONS: Viscore-300 showed excellent precision and accuracy and it might be a good instrument for reporting WBV quickly and accurately.
Blood Vessels ; Blood Viscosity ; Female ; Humans ; Male ; Microfluidics