A Rapid and Low Cost Manufacturing for Polymeric Microfluidic Devices

2012 ◽  
Vol 579 ◽  
pp. 348-356 ◽  
Author(s):  
Pin Chuan Chen ◽  
Zhi Ping Wang
Keyword(s):  
Microfluidic Device ◽  
Low Cost ◽  
Mold Insert ◽  
Microfluidic Devices ◽  
Rapid Manufacturing ◽  
Dna Fragments ◽  
Chain Reaction ◽  
Microelectromechanical System ◽  
Polymerase Chain ◽  
Low Cost Manufacturing

A rapid manufacturing process was demonstrated to fabricate a microfluidic device to amplify specific DNA fragments in less than 8 hours. Microfluidics was derived from microelectromechanical system (MEMS) with lithography technique on the substrates of silicon and glass, which made the microfluidic product have a higher fabrication cost and laborious fabrication steps. This rapid approach only requires three steps for a PDMS microfluidic device: metal mold insert manufacturing, PDMS casting, and glass bonding. Each step did not require complicated equipments or procedures, and make this approach very attractive in rapid prototyping and experimental optimization with microfluidic devices. In this work, a brass mold insert was manufactured by a micromilling machine, followed by the standard PDMS casting and glass bonding to fabricate a microfluidic device. Polymerase chain reaction (PCR) to amplify specific DNA fragments, a typical microfluidic example, was successfully realized on this PDMS microfluidic device. This rapid and low cost (compared to conventional lithography) fabrication approach can provide researchers a lower entry to polymeric lab-on-a-chip either on PDMS or thermoplastic substrate for various applications.

scholarly journals Molecular Characterization and Classification of Phytoplasmas Associated with Canola Yellows and a New Phytoplasma Strain Associated with Dandelions

Plant Disease ◽  
2001 ◽  
Vol 85 (1) ◽  
pp. 76-79 ◽  
Author(s):  
Keri Wang ◽  
Chuji Hiruki
Keyword(s):  
Fragment Length Polymorphism ◽  
Rflp Analysis ◽  
Universal Primers ◽  
Dna Fragments ◽  
Chain Reaction ◽  
Aster Yellows ◽  
Distinct Subgroup ◽  
16S Ribosomal Dna ◽  
Polymerase Chain

DNA isolated from symptomatic canola (Brassica napus, Brassica rapa) and dandelion (Taraxacum officinale) was used to amplify 16S ribosomal DNA fragments by polymerase chain reaction using two pairs of universal primers P1/P6 and R16F2n/R2. Restriction fragment length polymorphism (RFLP) analysis of the amplified DNA fragments using endonucleases AluI, HhaI, HpaII, MseI, RsaI, and Sau 3AI revealed two distinct types of phytoplasmas in canola with similar symptoms. One had the same RFLP profiles as the phytoplasmas in subgroup 16SrI-A, whereas the other one had RFLP profiles similar to those of phytoplasmas in subgroup 16SrI-B. Phytoplasmas were detected in symptomatic dandelion plants that were collected from canola and alfalfa fields where severe alfalfa witches'-broom occurred. Comparative studies indicated that two different phytoplasmas were associated with the dandelion plants. One was identified as a member of subgroup 16SrI-A, whereas another one was classified as a member of a distinct subgroup in the aster yellows group on the basis of the unique RFLP patterns.

scholarly journals Micropipette-Based Microfluidic Device for Monodisperse Microbubbles Generation

Micromachines ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 387
Author(s):  
Carlos Toshiyuki Matsumi ◽  
Wilson José da Silva ◽  
Fábio Kurt Schneider ◽  
Joaquim Miguel Maia ◽  
Rigoberto E. M. Morales ◽  
...  
Keyword(s):  
Electric Fields ◽  
Microfluidic Device ◽  
Soft Lithography ◽  
Low Cost ◽  
Characteristic Curve ◽  
Microfluidic Devices ◽  
Average Diameter ◽  
Internal Diameter ◽  
Medical Diagnostic ◽  
Average Size

Microbubbles have various applications including their use as carrier agents for localized delivery of genes and drugs and in medical diagnostic imagery. Various techniques are used for the production of monodisperse microbubbles including the Gyratory, the coaxial electro-hydrodynamic atomization (CEHDA), the sonication methods, and the use of microfluidic devices. Some of these techniques require safety procedures during the application of intense electric fields (e.g., CEHDA) or soft lithography equipment for the production of microfluidic devices. This study presents a hybrid manufacturing process using micropipettes and 3D printing for the construction of a T-Junction microfluidic device resulting in simple and low cost generation of monodisperse microbubbles. In this work, microbubbles with an average size of 16.6 to 57.7 μm and a polydispersity index (PDI) between 0.47% and 1.06% were generated. When the device is used at higher bubble production rate, the average diameter was 42.8 μm with increased PDI of 3.13%. In addition, a second-order polynomial characteristic curve useful to estimate micropipette internal diameter necessary to generate a desired microbubble size is presented and a linear relationship between the ratio of gaseous and liquid phases flows and the ratio of microbubble and micropipette diameters (i.e., Qg/Ql and Db/Dp) was found.

scholarly journals Design and development of polymerase chain reaction thermal cycler using proportional-integral temperature controller

2018 ◽  
Vol 14 (2) ◽  
pp. 213-218
Author(s):  
Chong Kim Soon ◽  
Nawoor Anusha Devi ◽  
Kok Beng Gan ◽  
Sue-Mian Then
Keyword(s):  
Polymerase Chain Reaction ◽  
Low Cost ◽  
Maximum Temperature ◽  
Gradient System ◽  
Chain Reaction ◽  
Temperature Controller ◽  
Proportional Integral ◽  
Integral Temperature ◽  
Polymerase Chain ◽  
Thermal Cycler

A thermal cycler is used to amplify segments of DNA using the polymerase chain reaction (PCR). It is an instrument that requires precise temperature control and rapid temperature changes for certain experimental protocols. However, the commercial thermal cyclers are still bulky, expensive and limited for laboratory use only.  As such it is difficult for on-site molecular screening and diagnostics. In this work, a portable and low cost thermal cycler was designed and developed. The thermal cycler block was designed to fit six microcentrifuge tubes. A Proportional-Integral temperature controller was used to control the thermal cycler block temperature. The results showed that the maximum temperature ramp rate of the developed thermal cycler was 5.5 °C/s. The proportional gain (Kp) and integral gain (Ki) of the PI controller were 15 A/V and 1.8 A/Vs respectively. Finally, the developed thermal cycler successfully amplified six DNA samples at the expected molecular weight of 150 base pair. It has been validated using the Eppendorf Mastercycler nexus gradient system and gel electrophoresis analysis

Inline biofilm monitoring based on near-infrared spectroscopy with ultracompact spectrometer technology

NIR news ◽  
2020 ◽  
Vol 31 (7-8) ◽  
pp. 9-13
Author(s):  
Robert Zimmerleiter ◽  
Elisabeth Leiss-Holzinger ◽  
Eva Maria Wagner ◽  
Kathrin Kober-Rychli ◽  
Martin Wagner ◽  
...  
Keyword(s):  
Near Infrared ◽  
Spectral Response ◽  
Principal Component ◽  
Cost Effective ◽  
Sensor Surface ◽  
Chain Reaction ◽  
Microelectromechanical System ◽  
Infrared Spectral ◽  
Infrared Measurement ◽  
Polymerase Chain

In this article, we demonstrate a promising inline near-infrared measurement scheme for 24/7 biofilm monitoring based on cost-effective microelectromechanical system-based spectrometer technology. The shown near-infrared spectral data, acquired at a beer-canning line during a representative time span of 10 days, are analyzed by means of principal component analysis and the performance of the monitoring system and its capability to identify biofilms on its sensor surface are investigated by comparing spectral response with results of offline polymerase chain reaction measurements of smear samples. Correlations between presence of a biofilm and its thickness with scores on PC1 and PC2, respectively, were observed.

scholarly journals Low Cost Micro Milling Machine for Prototyping Plastic Microfluidic Devices

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 707 ◽  
Author(s):  
Md Mubarak Hossain ◽  
Tanzilur Rahman
Keyword(s):  
Developing Countries ◽  
Microfluidic Device ◽  
Low Cost ◽  
Microfluidic Devices ◽  
Micro Milling ◽  
Biological Research ◽  
Milling Machine ◽  
Plastic Materials ◽  
Milling Machines

Micro-milling is one of the commonly used methods of fabrication of microfluidic devices necessary for cell biological research and application. Commercial micro-milling machines are expensive, and researchers in developing countries can’t afford them. Here, we report the design and the development of a low-cost (<130 USD) micro milling machine and asses the prototyping capabilities of microfeatures in plastic materials. We demonstrate that the developed machine can be used in fabricating the plastic based microfluidic device.

Plasma vs. serum in circulating tumor DNA measurement: characterization by DNA fragment sizing and digital droplet polymerase chain reaction

2020 ◽  
Vol 58 (4) ◽  
pp. 527-532 ◽  
Author(s):  
Jee-Soo Lee ◽  
Miyoung Kim ◽  
Moon-Woo Seong ◽  
Han-Sung Kim ◽  
Young Kyung Lee ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Circulating Tumor Dna ◽  
Analytical Sensitivity ◽  
Dna Fragments ◽  
Chain Reaction ◽  
Specimen Type ◽  
Dna Fragment ◽  
Polymerase Chain ◽  
Ctdna Analysis ◽  
Tumor Dna

AbstractBackgroundChoosing the specimen type is the first step of the pre-analytical process. Previous reports suggested plasma as the optimal specimen for circulating tumor DNA (ctDNA) analysis. However, head-to-head comparisons between plasma and serum using platforms with high analytical sensitivity, such as droplet digital polymerase chain reaction (ddPCR), are limited, and several recent studies have supported the clinical utility of serum-derived ctDNA. This study aimed to compare the DNA profiles isolated from plasma and serum, characterize the effects of the differences between specimens on ctDNA measurement, and determine the major contributors to these differences.MethodsWe isolated cell-free DNA (cfDNA) from 119 matched plasma/serum samples from cancer patients and analyzed the cfDNA profiles by DNA fragment sizing. We then assessed KRAS mutations in ctDNA from matched plasma/serum using ddPCR.ResultsThe amount of large DNA fragments was increased in serum, whereas that of cfDNA fragments (<800 bp) was similar in both specimens. ctDNA was less frequently detected in serum, and the KRAS-mutated fraction in serum was significantly lower than that in plasma. The differences in ctDNA fractions between the two specimen types correlated well with the amount of large DNA fragments and white blood cell and neutrophil counts.ConclusionsOur results provided detailed insights into the differences between plasma and serum using DNA fragment sizing and ddPCR, potentially contributing to ctDNA analysis standardization. Our study also suggested that using plasma minimizes the dilution of tumor-derived DNA and optimizes the sensitivity of ctDNA analysis. So, plasma should be the preferred specimen type.

Direct Sequencing of DNA Fragments Amplified with Single Primers by Polymerase Chain Reaction without Cloning

1996 ◽  
Vol 241 (1) ◽  
pp. 136-139 ◽  
Author(s):  
Masayoshi Iizuka ◽  
Yuki Sugiyama ◽  
Shigeru Iida ◽  
Takao Sekiya
Keyword(s):  
Polymerase Chain Reaction ◽  
Direct Sequencing ◽  
Dna Fragments ◽  
Chain Reaction ◽  
Polymerase Chain

scholarly journals Cerebral Ischemia Produces Laddered DNA Fragments Distinct from Cardiac Ischemia and Archetypal Apoptosis

1999 ◽  
Vol 19 (5) ◽  
pp. 502-510 ◽  
Author(s):  
John P. MacManus ◽  
Henry Fliss ◽  
Edward Preston ◽  
Ingrid Rasquinha ◽  
Ursula Tuor
Keyword(s):  
Cerebral Ischemia ◽  
Cortical Neurons ◽  
Electrophoretic Pattern ◽  
Type I ◽  
Dna Fragments ◽  
Chain Reaction ◽  
Adult Rats ◽  
Ischemic Brain ◽  
Dna Backbone ◽  
Polymerase Chain

The electrophoretic pattern of laddered DNA fragments which has been observed after cerebral ischemia is considered to indicate that neurons are dying by apoptosis. Herein the authors directly demonstrate using ligation-mediated polymerase chain reaction methods that 99% of the DNA fragments produced after either global or focal ischemia in adult rats, or produced after hypoxia-ischemia in neonatal rats, have staggered ends with a 3' recess of approximately 8 to 10 nucleotides. This is in contrast to archetypal apoptosis in which the DNA fragments are blunt ended as seen during developmental programmed cell death in dying cortical neurons, neuroblastoma, or thymic lymphocytes. It is not simply ischemia that results in staggered ends in DNA fragments because ischemic myocardium is similar to archetypal apoptosis with a vast majority of blunt-ended fragments. It is concluded that the endonucleases that produce this staggered fragmentation of the DNA backbone in ischemic brain must be different than those of classic or type I apoptosis.

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