ABSTRACT
Here a microfluidic chip with 'micro-dam' and 'micro-gap' has been designed and fabricated. It could isolate different cells and flow of medium in each region. It was found that the chip could realize the cells co-culture and patterning of human lung adenocarcinoma cell (A549), human embryonic lung fibroblast (HLF-1) and human endothelial cells (HUVECs), respectively. After 72 hours of culture, three kinds of cells grew well. It provided a developing technical platform for cell related research.
ABSTRACT
Based on the Android platform, a portable electrochemical analyzer was designed for the detection of heavy metal ions. Its output voltage range was ±3 V with accuracy of 0. 1% and resolution of <1 mV. The current acquisition range was±10 mA with accuracy of 0. 1% and the minimum resolution of 10 pA. With the human-computer interaction advantage of Android smart devices, professional and fast detection mode which could meet the needs of professional and ordinary users respectively were developed to simplify the complex process of electrochemical detection and analysis. Some common heavy metal ions including copper, cadmium, lead and mercury were detected with this detector. The results of linearity, repeatability and accuracy were satisfactory.
ABSTRACT
We report here a novel membrane transfer-based DNA detection method, in which alkaline phosphatase labeled gold nanoparticle (AuNP) probes were used as a means to amplify the detection signal. In this method, the capture probe P1, complimentary to the 3' end of target DNA, was immobilized on the chip. The multi-component AuNP probes were prepared by co-coating AuNPs with the detecting probe P2, complimentary to the 5' end of target DNA, and two biotin-labeled signal probes (T10 and T40) with different lengths. In the presence of target DNA, DNA hybridization led to the attachment of AuNPs on the chip surface where specific DNA sequences were located in a "sandwich" format. Alkaline phosphatase was then introduced to the surface via biotine-streptavidin interaction. By using BCIP/NBT alkaline phosphatase color development kit, a colorimetric DNA detection was achieved through membrane transfer. The signal on the membrane was then detected by the naked eye or an ordinary optical scanner. The method provided a detection of limit of 1 pmol/L for synthesized target DNA and 0.23 pmol/L for PCR products of Mycobacterium tuberculosis 16S rDNA when the ratio of probes used was 9:1:1 (T10:T40:P2). The method described here has many desirable advantages including high sensitivity, simple operation, and no need of sophisticated equipment. The method can be potentially used for reliable biosensings.
Subject(s)
Humans , Colorimetry , Methods , DNA Probes , Chemistry , Genetics , DNA, Bacterial , Genetics , Gold , Chemistry , Metal Nanoparticles , Chemistry , Mycobacterium tuberculosis , Nucleic Acid Hybridization , Methods , Oligonucleotide Array Sequence Analysis , MethodsABSTRACT
We developed a novel microfluidic cell chip, which enabled drug delivery, fluid control and cell co-culture. The device consisted of an array of 6x6 cell culture chambers, a drug gradient generator and fluidic control valves. Micro-dam structures of the chambers were able to trap cells while loading and drug gradient network generated drug gradient of 6 different concentrations. Also we applied hydraulic valves to control the microfluid and simulate the microenvironment of cells. We had investigated the viability of co-culturing cells in the chip and the ability for drug screening. This microfluidic cell chip has the potential in cell-based research of high throughput drug screening.
Subject(s)
Humans , Biosensing Techniques , Methods , Cells, Cultured , Drug Evaluation, Preclinical , Methods , Endothelial Cells , Cell Biology , Hepatocytes , Cell Biology , Microfluidic Analytical Techniques , Methods , Microfluidics , Methods , Umbilical Veins , Cell BiologyABSTRACT
The ability to pattern multiple cells through precise surface engineering of cell culture substrates has promoted the development of cellular bioassays, such as differentiation, interaction and molecular signaling pathways. There are several well developed ways to pattern cells. This report describes a method for patterning multiple types of cells based on microfluidics and self-assembled monolayers. We developed two types of micro-dam structures by soft-lithography to locate cells precisely and modified the substrate by a kind of self-assembled monolayer with property of electrochemical desorption to confine cells in specific areas. Finally we could pattern an array of two different types of cells closely and precisely. Cells were confined in specific areas but still shared the same microenvironment, so they could interact through soluble molecules. The substrate was transparent and open, so we could easily apply several instruments for research. With these merits, this cell chip is appropriate for investigating the interaction between different types of cells.
Subject(s)
Humans , Cell Adhesion , Physiology , Cell Line, Tumor , Cell Proliferation , Cells , Cell Biology , Electrochemistry , Methods , Endothelial Cells , Cell Biology , Liver Neoplasms , Pathology , Microfluidics , Methods , Substrate Specificity , Tissue Engineering , Methods , Umbilical Veins , Cell BiologyABSTRACT
In this article, a cell culture microchip was fabricated on the SU-8 mold based on polymer-MEMS process. In the microchip, the cell culture area was separated with microchannel by a microgap, which kept the cell culture area independent, but also regulated the micro-environment of extracellular matrix by the microfluidic flow. The cell culture microchip provided a new platform for cell research.
