scholarly journals Continuous Microfluidic Purification of DNA Using Magnetophoresis

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 187
Author(s):  
Ying Xu ◽  
Zhen Zhang ◽  
Zhen Su ◽  
Xiaoxiang Zhou ◽  
Xiaoming Han ◽  
...  

Automatic microfluidic purification of nucleic acid is predictable to reduce the input of original samples and improve the throughput of library preparation for sequencing. Here, we propose a novel microfluidic system using an external NdFeB magnet to isolate DNA from the polymerase chain reaction (PCR) mixture. The DNA was purified and isolated when the DNA-carrying beads transported to the interface of multi-laminar flow under the influence of magnetic field. Prior to the DNA recovery experiments, COMSOL simulations were carried out to study the relationship between trajectory of beads and magnet positions as well as fluid velocities. Afterwards, the experiments to study the influence of varying velocities and input of samples on the DNA recovery were conducted. Compared to experimental results, the relative error of the final position of beads is less than 10%. The recovery efficiency decreases with increase of input or fluid velocity, and the maximum DNA recovery efficiency is 98.4% with input of l00 ng DNA at fluid velocity of 1.373 mm/s. The results show that simulations significantly reduce the time for parameter adjustment in experiments. In addition, this platform uses a basic two-layer chip to realize automatic DNA isolation without any other liquid switch value or magnet controller.

2017 ◽  
Vol 69 (6) ◽  
pp. 1443-1450 ◽  
Author(s):  
M.P. Campos ◽  
M.F. Madeira ◽  
D.A. Silva ◽  
M.S. Solcà ◽  
O.M. Espíndola ◽  
...  

ABSTRACT The purpose of the present work was to evaluate the accuracy of quantitative polymerase chain reaction (qPCR) performed on samples of fresh frozen tissue (FT) and formalin-fixed, paraffin-embedded (FFPE) healthy skin. This is a validation study conducted with samples from 46 dogs from an endemic area in Brazil. After sample collection, DNA extractions were conducted using commercial kits and qPCR was oriented to kinetoplast DNA (kDNA) targets of the Leishmania infantum species. The results obtained for the FFPE samples showed 63.6% sensitivity and 77.1% specificity, whereas those obtained for the FT samples showed 100% and 48.6%, respectively. Poor agreement was observed for the results of the qPCR technique with FT and FFPE samples. Our results suggest freezing as the most suitable conservation method for the formation of sample databases considering DNA recovery


2007 ◽  
Vol 42 (10) ◽  
pp. 1249-1255 ◽  
Author(s):  
Cibele dos Santos Ferrari ◽  
Luciana Lehmkuhl Valente ◽  
Fábio Cristiano Angonesi Brod ◽  
Caroline Tagliari ◽  
Ernani Sebastião Sant'Anna ◽  
...  

1998 ◽  
Vol 262 (1) ◽  
pp. 79-82 ◽  
Author(s):  
Günther Bahnweg ◽  
Steffen Schulze ◽  
Evelyn M. Möller ◽  
Hilkea Rosenbrock ◽  
Christian Langebartels ◽  
...  

2018 ◽  
Vol 94 ◽  
Author(s):  
K.J.L. Monteiro ◽  
D.A. Calegar ◽  
F.A. Carvalho-Costa ◽  
L.H. Jaeger ◽  

AbstractDespite the reduction in the prevalence of soil-transmitted helminthiases in many regions of the world, morbidity rates remain high in some rural regions. The Kato–Katz technique is a simple, inexpensive and field-applicable tool commonly used for the diagnosis and worm-burden characterization of these infections. Molecular studies have revolutionized our understanding of the epidemiology and evolutionary genetics of parasites. In this study we recovered helminthic DNA from Kato–Katz slides (n = 93) prepared in 2011 in the Brazilian Amazon. We achieved DNA recovery by polymerase chain reaction (PCR) in 84% of cases for Ascaris sp. and 75% of cases for hookworms. The sequencing confirmed the specific species of the amplicons. The slides stored for a few years could be analysed using this methodology, allowing access to DNA from a large collection of samples. We must consider the Kato–Katz thick smears as a source of helminth DNA. This can significantly reduce logistical difficulties in the field in terms of obtaining, preserving, transporting and initial processing of samples.


2018 ◽  
Vol 35 (1) ◽  
pp. 11-19
Author(s):  
Kuder Reshma Shabnam ◽  
Dharmapuri Gangappa ◽  
Gundala Harold Philip

Evaluation of the toxic effects of a widely used synthetic pyrethroid, deltamethrin (DM), was carried out in this study. This pesticide is preferred for pest control because of its low environmental persistence and toxicity. We investigated the expression pattern of four genes, namely, you ( you), yot ( you-too), momo ( mom) and ubo ( u-boot) during early development of zebrafish, that is, from 12 hpf to 48 hpf stages. These stages are selected as most of the important developmental aspects take place during this period. All four genes are known to play a vital role in development of notochord and somites. To understand the effect of DM on development, embryos of 4 hpf stage were exposed to two concentrations (100 and 200 µg/L) of DM, and observations were made at 12, 24 and 48 hpf stages. Our earlier studies have shown phenotypic abnormalities such as notochord bending, tail deformation, yolk sac and pericardial edema, lightening of body and eye pigmentation and interfered in somite patterning, during these stages of development. Understanding the relationship of phenotypic abnormalities with these four genes has been our primary objective. These four genes were analyzed by Reverse transcription (RT)-polymerase chain reaction and intensity of the bands has shown induction in their expression after exposure to the toxicant. In spite of the expression of genes, it was noticed that DM caused abnormalities. It can be said from the results that translational pathway could have been affected.


Author(s):  
Dwiyitno Dwiyitno ◽  
Stefan Hoffman ◽  
Koen Parmentier ◽  
Chris Van Keer

Fish and seafood products has been commonly targeted for fraudulent activities. For that reason, authentication of fish and seafood products is important to protect consumers from fraudulent and adulteration practices, as well as to implement traceability regulation. From the viewpoint of food safety, authenticity is beneficial to protect public from serious food poisoning incidents, such as due to ingestion of toxic species. Since DNA based identification depends on the nucleic acid polymerase chain reaction (PCR), the quantity and quality/purity of DNA will contribute significantly to the species authentication. In the present study, different DNA extraction and purification methods (3 classical methods and one commercial kit) were compared to produce the better isolated DNA for PCR amplification. Additionally, different methods for the estimation of DNA concentration and purity which is essential for PCR amplification efficiency were also evaluated. The result showed that classical DNA extraction methods (based on TNES-Urea) yielded a higher amount of DNA (11.30-323.60 ng/g tissue) in comparison to commercial kit/Wizard Promega (5.70-83.45 ng/g tissue). Based on the purity of DNA extract (A260/280), classical DNA extraction method produced relatively similar on DNA quality to the commercial kit (1.79-2.12). Interestingly, all classical methods produced DNA with A260/280 ratio of more than 2.00 on the blue mussel, in contrast with commercial kit. The commercial kit also produced better quality of DNA compared to the classical methods, showing the higher efficiency in PCR amplification. NanoDrop is promising as cheap, robust and safe UV-spectrophotometer method for DNA quantification, as well as the purity evaluation.Keywords: seafood authenticity, DNA isolation, polymerase chain reaction, NanoDrop, Picogreen


Author(s):  
Ali Ahmet Kilimcioğlu ◽  
Nogay Girginkardeşler ◽  
Tuba Oyur ◽  
Selin Bölük Sabuncu ◽  
Didem Düzyol Azak ◽  
...  

Objective: It was aimed to develop a new Multiplex Polymerase Chain Reaction (PCR) protocol with isolates obtained from local patients for the diagnosis of Blastocystis sp., Cryptosporidium sp. and Giardia intestinalis, which can cause severe gastrointestinal system complaints especially in immunocompromised patients and children. Method: DNA isolation was performed with a commercial kit from three stool samples of different patients whose microscopic examination showed dense amounts of Blastocystis sp., Cryptosporidium sp. and Giardia intestinalis. First, a special PCR protocol has been developed for each protozoon. Then, the multiplex PCR protocol, in which these three protozoa can be diagnosed together, was optimized. Results: In the multiplex PCR protocol performed after DNA isolation, bands of 95 bp., 227 bp. and 258 bp. were obtained for Cryptosporidium sp., Blastocystis sp. and G. intestinalis, respectively. Conclusion: Blastocystis sp., Cryptosporidium sp. and Giardia intestinalis were diagnosed by multiplex PCR with the original protocol developed. Due to the difficulties in using different methods in parasitological examination, by adding other protozoa important for public health to this optimized protocol, it will be possible to detect a large number of parasites with a single molecular method.


2007 ◽  
Vol 380 (1-2) ◽  
pp. 112-117 ◽  
Author(s):  
Young Geun Yang ◽  
Jong Yeol Kim ◽  
Young-Han Song ◽  
Doo-Sik Kim

2012 ◽  
Vol 51 (No. 5) ◽  
pp. 180-192 ◽  
Author(s):  
J. Hosek ◽  
P. Svastova ◽  
M. Moravkova ◽  
I. Pavlik ◽  
M. Bartos

Mycobacteria cause serious infections in animals and human beings. Huge economic losses on farms are caused by selected species of this wide family. A high risk of transmission of infection from animal to human exists. The knowledge of exact pathogen characteristics is an important factor which can improve quick and adequate healing. Cultivation and determination of phenotype is still the “gold standard”, but has the disadvantage of taking a long time and also low detection limit. Biochemical characterisation of isolates is not exact, and it is expensive. A more popular method used is the amplification of specific loci by polymerase chain reaction (PCR). For this method, the isolation of sufficient amounts of purified DNA is necessary. In this paper the most frequently used method for DNA isolation from live mycobacterial cells, body fluids, tissues, histological samples and forensic materials are outlined. This paper assists only as guide for these methods, so we describe them briefly.


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