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Cell-free protein synthesis: advances on production process for biopharmaceuticals and immunobiological products. Biotechniques (IF 1.541) Pub Date : 2021-01-20 Camila Hiromi Chiba; Marcos Camargo Knirsch; Adriano Rodrigues Azzoni; Antonio R Moreira; Marco Antonio Stephano
Biopharmaceutical products are of great importance in the treatment or prevention of many diseases and represent a growing share of the global pharmaceutical market. The usual technology for protein synthesis (cell-based expression) faces certain obstacles, especially with 'difficult-to-express' proteins. Cell-free protein synthesis (CFPS) can overcome the main bottlenecks of cell-based expression
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Urea-based amino sugar agent clears murine liver and preserves protein fluorescence and lipophilic dyes. Biotechniques (IF 1.541) Pub Date : 2021-01-20 Michelle Hough; Michael Fenlon; Alison Glazier; Celia Short; Gerardo Esteban Fernandez; Jiabo Xu; Elaa Mahdi; Kinji Asahina; Kasper S Wang
Five established clearing protocols were compared with a modified and simplified method to determine an optimal clearing reagent for three-dimensionally visualizing fluorophores in the murine liver, a challenging organ to clear. We report successful clearing of whole liver lobes by modification of an established protocol (UbasM) using only Ub-1, a urea-based amino sugar reagent, in a simpler protocol
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Metagenomics: preventing future pandemics. Biotechniques (IF 1.541) Pub Date : 2021-1-16 Abigail Sawyer; Tristan Free; Joseph Martin
Metagenomic approaches have been key to successful tracing and outbreak management during the COVID-19 pandemic. How can we use this knowledge to better prepare, strategize and prevent future pandemics? [Formula: see text].
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Simple and efficient custom transcription activator-like effector gene synthesis via twin primer assembly. Biotechniques (IF 1.541) Pub Date : 2021-01-08 Song Wang; Yan Yu; Yuhualei Pan; Huan Wang; Yushang Zhao; Mengyao Qu; Yanbing Zhu
Transcription activator-like effector (TALE) nucleases (TALENs) efficiently recognize and cleave DNA in a sequence-dependent manner. However, current TALE custom synthesis methods are either complicated or expensive. Here we report a simple and low-cost method for TALE construct assembly. This method utilizes the denaturation/reannealing nature of double-stranded DNA to create a unique single-stranded
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High-purity DNA extraction from animal tissue using picking in the TRIzol-based method. Biotechniques (IF 1.541) Pub Date : 2020-12-18 Ye Yin Bo; Li Dong Liang; Yang Jiang Hua; Zhang Zhao; Mei Si Yao; Liu Bao Shan; Chen Ze Liang
TRIzol is used for the extraction of RNA, DNA and proteins from tissues or cells. Here, we present a simple picking method to extract DNA from tissues using TRIzol. Spectrophotometric analysis showed that the 260/280 and 260/230 nm optical density ratio of the picking method's DNA is ideal and better than that obtained by the classic TRIzol method. Gel electrophoresis showed that there was no RNA contamination
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Injection of Evans blue dye to fluorescently label and image intact vasculature. Biotechniques (IF 1.541) Pub Date : 2020-12-18 Samuel E Honeycutt; Lori L O'Brien
Blood vessels perform critical functions in both health and disease. Understanding how vessels form, pattern and respond to damage is essential. However, labeling and imaging the vasculature to ascertain these properties can be difficult and time-consuming. Here, the authors present a novel methodology for rapidly and efficiently labeling whole vascular networks in vivo by exploiting the fluorescent
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Microscopy automation on a budget: capturing high-speed multi-labelled events with LED Illumination Systems. Biotechniques (IF 1.541) Pub Date : 2020-12-16
Capturing fast cellular processes with widefield fluorescence microscopy and multiple fluorophores has historically required the addition of motorised components. The light source has often been overlooked as an affordable means of achieving multi-wavelength imaging, but LEDs have changed the game. Here we compare typical configurations for automated illumination systems in terms of speed, cost and
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A short interspersed nuclear element-based quantitative PCR assay for simultaneous human and dog DNA detection and quantification. Biotechniques (IF 1.541) Pub Date : 2020-12-14 James W Liang; Heather Miller Coyle
This study aimed to develop a quantitative PCR assay to simultaneously quantify human and dog DNA in a multispecies mixture to inform downstream analyses in routine forensic casework and scientific research. The human target is the Alu Yb8 element, which has approximately 2000 copies per cell, and the canine target is the SINEC_Cf element, which has approximately 200,000 copies per cell. The internal
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tANCHOR: a novel mammalian cell surface peptide display system. Biotechniques (IF 1.541) Pub Date : 2020-12-14 Daniel Ivanusic; Kazimierz Madela; Heidi Burghard; Gudrun Holland; Michael Laue; Norbert Bannert
A novel tool for the presentation of peptides and small proteins on the surface of human cells has been developed. Our tANCHOR system utilizes tetraspanin anchors containing heterologous amino acid sequences inserted instead of the large extracellular loop. This technology allows a highly effective extracellular display of epitopes for antibody binding studies and many other potential applications
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A low-cost platform suitable for sequencing-based recovery of natural variation in understudied plants. Biotechniques (IF 1.541) Pub Date : 2020-12-14 Rachel Howard-Till; Claudia E Osorio; Bradley J Till
Genetic characterization of wild and cultivated plants provides valuable knowledge for conservation and agriculture. DNA sequencing technologies are improving, and costs are dropping. Yet analysis of many species is hindered because they grow in regions that lack infrastructure for advanced molecular biology. The authors developed and adapted low-cost methods that address these issues. Tissue was collected
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3D-printed assistive pipetting system for gel electrophoresis for technicians with low acuity vision. Biotechniques (IF 1.541) Pub Date : 2020-12-14 Alex Viqian Huynh; Phillip Stein; Ethan D Buhr
In molecular biology laboratories, many tasks require fine motor control and high acuity vision. For example, lab technicians with visual impairment experience difficulty loading samples into the small wells of a horizontal agarose gel. We have developed a 3D-printable gel loading system which allows technicians with low-contrast vision to load gels correctly. It includes a casting tray, a bridge,
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Protocols for the preparation and characterization of decellularized tissue and organ scaffolds for tissue engineering. Biotechniques (IF 1.541) Pub Date : 2020-12-14 Dar-Jen Hsieh; Periasamy Srinivasan; Ko-Chung Yen; Yi-Chun Yeh; Yun-Ju Chen; Hung-Chou Wang; Yih-Wen Tarng
Extracellular matrix (ECM) scaffolds are extensively used in tissue engineering studies and numerous clinical applications for tissue and organ reconstructions. Due to the global severe shortage of human tissues and organs, xenogeneic biomaterials are a common source for human tissue engineering and regenerative medicine applications. Traditional methods for decellularization often disrupt the 3D architecture
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An online tool for fetal fraction prediction based on direct size distribution analysis of maternal cell-free DNA. Biotechniques (IF 1.541) Pub Date : 2020-11-30 Luca Bedon; Josef Vuch; Simeone Dal Monego; Germana Meroni; Vanna Pecile; Danilo Licastro
The discovery of circulating fetal DNA in the plasma of pregnant women has greatly promoted advances in noninvasive prenatal testing. Screening performance is enhanced with higher fetal fraction and analysis of samples whose fetal DNA fraction is lower than 4% are unreliable. Although current approaches to fetal fraction measurement are accurate, most of them are expensive and time consuming. Here
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A simple method of drying polyacrylamide slab gels that eliminates cracking. Biotechniques (IF 1.541) Pub Date : 2020-11-23 Ghanshyam D Heda
The polyacrylamide slab gel is the most common gel format for analyzing protein samples by electrophoresis. Drying these gels is useful in many biological applications; for example, autoradiography, in which radiolabeled proteins are separated to enable their detection and identification. Dried protein gels can also serve as an ideal method of preserving the gel itself for permanent record-keeping
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Increased sensitivity using real-time dPCR for detection of SARS-CoV-2. Biotechniques (IF 1.541) Pub Date : 2020-11-23 Kyra Duong; Jiajia Ou; Zhaoliang Li; Zhaoqing Lv; Hao Dong; Tao Hu; Yunyun Zhang; Ava Hanna; Skyler Gordon; Gogce Crynen; Steven R Head; Phillip Ordoukhanian; Yan Wang
A real-time dPCR system was developed to improve the sensitivity, specificity and quantification accuracy of end point dPCR. We compared three technologies - real-time qPCR, end point dPCR and real-time dPCR - in the context of SARS-CoV-2. Some improvement in limit of detection was obtained with end point dPCR compared with real-time qPCR, and the limit of detection was further improved with the newly
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How has the COVID-19 pandemic impacted PCR? Biotechniques (IF 1.541) Pub Date : 2020-11-23 Joseph Martin
The recent pandemic has posed perhaps the biggest challenge for PCR to date. Is PCR likely to be replaced or will it continue to stand the test of time? [Formula: see text].
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Generation of genetically tailored porcine liver cancer cells by CRISPR/Cas9 editing. Biotechniques (IF 1.541) Pub Date : 2020-11-23 Lobna Elkhadragy; Maureen R Regan; William M Totura; Kimia Dasteh Goli; Shovik Patel; Kelly Garcia; Matthew Stewart; Lawrence B Schook; Ron C Gaba; Kyle M Schachtschneider
Pigs provide a valuable large animal model for several diseases due to their similarity with humans in anatomy, physiology, genetics and drug metabolism. We recently generated a porcine model for TP53R167H and KRASG12D driven hepatocellular carcinoma (HCC) by autologous liver implantation. Here we describe a streamlined approach for developing genetically tailored porcine HCC cells by CRISPR/Cas9 gene
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Evidence-based point-of-care technology development during the COVID-19 pandemic. Biotechniques (IF 1.541) Pub Date : 2020-11-09 Tejasvi Parupudi; Neha Panchagnula; Sriram Muthukumar; Shalini Prasad
Since December 2019, the SARS-CoV-2 outbreak that began in Wuhan, China has spread to nearly every continent and become a global health concern. Although much has been discovered about COVID-19 and its pathogenesis, the WHO has identified an immediate need to increase the levels of testing for COVID-19 and identify the stages of the disease accurately for appropriate action to be taken by clinicians
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Dielectrophoretic characterization of dendritic cell deformability upon maturation. Biotechniques (IF 1.541) Pub Date : 2020-11-03 Anoop Menachery; Jiranuwat Sapudom; Abhishek Vembadi; Aseel Alatoom; Jeremy Teo; Mohammad A Qasaimeh
We have developed a rapid technique for characterizing the biomechanical properties of dendritic cells using dielectrophoretic forces. It is widely recognized that maturing of dendritic cells modulates their stiffness and migration capabilities, which results in T-cell activation triggering the adaptive immune response. Therefore it is important to develop techniques for mechanophenotyping of immature
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CRISPR vs COVID-19: how can gene editing help beat a virus? Biotechniques (IF 1.541) Pub Date : 2020-11-02 Jennifer Straiton
[Formula: see text] Known to be a sturdy weapon in a scientist's arsenal, how has the gene editing tool CRISPR been applied in the fight against COVID-19?
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Comparison of target enrichment strategies for ancient pathogen DNA. Biotechniques (IF 1.541) Pub Date : 2020-11-02 Anja Furtwängler; Judith Neukamm; Lisa Böhme; Ella Reiter; Melanie Vollstedt; Natasha Arora; Pushpendra Singh; Stewart T Cole; Sascha Knauf; Sébastien Calvignac-Spencer; Ben Krause-Kyora; Johannes Krause; Verena J Schuenemann; Alexander Herbig
In ancient DNA research, the degraded nature of the samples generally results in poor yields of highly fragmented DNA; targeted DNA enrichment is thus required to maximize research outcomes. The three commonly used methods - array-based hybridization capture and in-solution capture using either RNA or DNA baits - have different characteristics that may influence the capture efficiency, specificity
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pET expression vector customized for efficient seamless cloning. Biotechniques (IF 1.541) Pub Date : 2020-11-02 Dragana Dobrijevic; Lily A Nematollahi; Helen C Hailes; John M Ward
Here we present a modification of the widely used pET29 expression vector for use in rapid and straightforward parallel cloning via a gene replacement and Golden Gate strategy. The modification can be applied to other expression vectors for Gram-negative bacteria. We have used the modified vectors to clone large numbers of bacterial natural enzyme variants from genomic and metagenomic sources for applications
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A rapid, nondestructive method for vascular network visualization. Biotechniques (IF 1.541) Pub Date : 2020-10-28 Austin Veith; Aaron B Baker
The quantitative analysis of blood vessel networks is an important component in many animal models of disease. We describe a nondestructive technique for blood vessel imaging that visualizes in situ vasculature in harvested tissues. The method allows for further analysis of the same tissues with histology and other methods that can be performed on fixed tissue. Consequently, it can easily be incorporated
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Modeling performance of sample collection sites using whole exome sequencing metrics. Biotechniques (IF 1.541) Pub Date : 2020-10-26 Natallia Kalinava; Abraham Apfel; Robert Cartmell; Sujaya Srinivasan; Ming-Shan Chien; Kyung In Kim; Ryan Golhar; Kathryn E Bednarz; Saumya Pant; Joseph Szustakowski; Scott D Chasalow; Ariella Sasson; Stefan Kirov
Although next-generation sequencing assays are routinely carried out using samples from cancer trials, the sequencing data are not always of the required quality. There is a need to evaluate the performance of tissue collection sites and provide feedback about the quality of next-generation sequencing data. This study used a modeling approach based on whole exome sequencing quality control (QC) metrics
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DNA recovery from Droplet Digital™ PCR emulsions using liquid nitrogen. Biotechniques (IF 1.541) Pub Date : 2020-10-26 Lara Dutra; Ole Franz; Veli-Mikko Puupponen; Marja Tiirola
Droplet microfluidics is a technology that enables the production and manipulation of small volumes. In biosciences, the most popular application of this technology is Droplet Digital™ PCR (ddPCR™), where parallel nanoliter-scale PCR assays are used to provide a high sensitivity and specificity for DNA detection. However, the recovery of PCR products for downstream applications such as sequencing can
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Methods for simultaneous and quantitative isolation of mitochondrial DNA, nuclear DNA and RNA from mammalian cells. Biotechniques (IF 1.541) Pub Date : 2020-10-26 Jean Nakhle; Tülin Özkan; Kateřina Lněničková; Philippe Briolotti; Marie-Luce Vignais
The aim of this study was to assess two protocols for their capacities to simultaneously isolate RNA, mtDNA and ncDNA from mammalian cells. We compared the Invitrogen TRIzol-based method and Qiagen DNeasy columns, using the HepG2 cell line and human primary glioblastoma stem cells. Both methods allowed the isolation of all three types of nucleic acids and provided similar yields in mtDNA. However,
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RNA interference approaches for plant disease control. Biotechniques (IF 1.541) Pub Date : 2020-10-19 Yen-Wen Kuo; Bryce W Falk
Plant diseases caused by a variety of pathogens can have severe effects on crop plants and even plants in natural ecosystems. Despite many effective conventional approaches to control plant diseases, new, efficacious, environmentally sound and cost-effective approaches are needed, particularly with our increasing human population and the effects on crop production and plant health caused by climate
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Developing drugs for the 'undruggable'. Biotechniques (IF 1.541) Pub Date : 2020-10-16 Abigail Sawyer
There are up to 650,000 'undruggable' protein-protein interactions (PPIs) in the human interactome that can be potentially considered as novel therapeutic targets. How does the 'undruggable' become 'druggable'?
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Quality control and statistical evaluation of combinatorial DNA libraries using nanopore sequencing. Biotechniques (IF 1.541) Pub Date : 2020-10-01 Cédric Lood; Hans Gerstmans; Yves Briers; Vera van Noort; Rob Lavigne
Protein engineering and synthetic biology applications increasingly rely on the assembly of modular libraries composed of thousands of different combinations of DNA building blocks. At present, the validation of such libraries is performed by Sanger sequencing analysis on a small subset of clones on an ad hoc basis. Here, we implement a systematic procedure for the comprehensive evaluation of combinatorial
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Effects of myofiber isolation technique on sarcolemma biomechanics. Biotechniques (IF 1.541) Pub Date : 2020-10-01 Karla P Garcia-Pelagio; Stephen Jp Pratt; Richard M Lovering
Isolated myofibers are commonly used to understand the function of skeletal muscle in vivo. This can involve single isolated myofibers obtained from dissection or from enzymatic dissociation. Isolation via dissection allows control of sarcomere length and preserves tendon attachment but is labor-intensive, time-consuming and yields few viable myofibers. In contrast, enzymatic dissociation is fast and
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A novel decatenation assay for DNA topoisomerases using a singly-linked catenated substrate. Biotechniques (IF 1.541) Pub Date : 2020-10-01 Nidda F Waraich; Shruti Jain; Sean D Colloms; William Marshall Stark; Nicolas P Burton; Anthony Maxwell
Decatenation is a crucial in vivo reaction of DNA topoisomerases in DNA replication and is frequently used in in vitro drug screening. Usually this reaction is monitored using kinetoplast DNA as a substrate, although this assay has several limitations. Here we have engineered a substrate for Tn3 resolvase that generates a singly-linked catenane that can readily be purified from the DNA substrate after
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Single-particle chemical force microscopy to characterize virus surface chemistry. Biotechniques (IF 1.541) Pub Date : 2020-10-01 Xue Mi; Caryn L Heldt
Two important viral surface characteristics are the hydrophobicity and surface charge, which determine the viral colloidal behavior and mobility. Chemical force microscopy allows the detection of viral surface chemistry in liquid samples with small amounts of virus sample. This single-particle method requires the functionalization of an atomic force microscope (AFM) probe and covalent bonding of viruses
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Molecularly imprinted polymers in biological applications. Biotechniques (IF 1.541) Pub Date : 2020-10-01 Zahra El-Schich; Yuecheng Zhang; Marek Feith; Sarah Beyer; Louise Sternbæk; Lars Ohlsson; Maria Stollenwerk; Anette Gjörloff Wingren
Molecularly imprinted polymers (MIPs) are currently widely used and further developed for biological applications. The MIP synthesis procedure is a key process, and a wide variety of protocols exist. The templates that are used for imprinting vary from the smallest glycosylated glycan structures or even amino acids to whole proteins or bacteria. The low cost, quick preparation, stability and reproducibility
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Critical role of three-dimensional tumorsphere size on experimental outcome. Biotechniques (IF 1.541) Pub Date : 2020-10-01 Suraj Kumar Singh; Sabiya Abbas; Ajit Kumar Saxena; Swasti Tiwari; Lokendra Kumar Sharma; Meenakshi Tiwari
Three-dimensional in vitro spheroids are a reliable model to study tumor biology and drug toxicity. However, inconsistencies exist in terms of seeding cell density that governs spheroid size and shape, influencing the experimental outcome. We investigated the effect of varying cell densities using glioblastoma cells on tumorsphere formation and their responsiveness to drug treatment. Our results demonstrated
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Double venipuncture is not required for adequate S-100B determination in melanoma patients. Biotechniques (IF 1.541) Pub Date : 2020-09-25 Samantha Damude,Anneke C Muller Kobold,Esther Bastiaannet,Schelto Kruijff,Harald J Hoekstra,Kevin P Wevers
S-100B is used in melanoma follow-up. This serum biomarker is also present in adipocytes; therefore, subcutaneous adipocytes trapped in the needle before performing a venipuncture could contaminate the serum. The aim was to study the influence of adipocyte contamination on blood samples used for S-100B analysis, possibly resulting in falsely elevated S-100B values. A total of 294 serum samples were
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A proper placental sampling for syncytin-1 analysis. Biotechniques (IF 1.541) Pub Date : 2020-09-24 Petra Priščáková,Miroslav Korbeľ,Zuzana Nižňanská,Katarína Letkovská,Katarína Sušienková,Vanda Repiská,Daniel Böhmer,Helena Gbelcová
Syncytin-1 (gene ERVW-1) has been proposed as a marker of pre-eclampsia and malfunctions in placental development. Placenta is heterogeneous tissue, hence the method of biopsy can significantly affect the outcome of analyses. A total of 44 placentae were analyzed by taking 3-30 samples from each. Relative levels of ERVW-1 expression in the placental biopsies were characterized by RT-qPCR. Evaluation
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Inhaler with electrostatic sterilizer and use of cationic amphiphilic peptides may accelerate recovery from COVID-19. Biotechniques (IF 1.541) Pub Date : 2020-06-17 Santi M Mandal,Souvik Panda
We explore the design of a smart inhaler with electrostatic sterilizer and propose the utilization of cationic amphiphilic peptides, independently or in conjunction with a bronchodilator, for COVID-19 patients to quickly improve wellbeing while maintaining a strategic distance to protect healthcare personnel from virus-containing aerosol or droplets during the process of inhalation.
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Contrast-enhanced ultrasound for the assessment of placental development and function. Biotechniques (IF 1.541) Pub Date : 2020-09-04 Victoria Hj Roberts,Antonio E Frias
The use of contrast agents as signal enhancers during ultrasound improves visualization and the diagnostic utility of this technology in medical imaging. Although widely used in many disciplines, contrast ultrasound is not routinely implemented in obstetrics, largely due to safety concerns of administered agents for pregnant women and the limited number of studies that address this issue. Here the
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Reduced serum methods for contact-based coculture of human dermal fibroblasts and epidermal keratinocytes. Biotechniques (IF 1.541) Pub Date : 2020-09-01 Snehal Kadam,Madhusoodhanan Vandana,Karishma S Kaushik
Direct contact-based coculture of human dermal fibroblasts and epidermal keratinocytes has been a long-standing and challenging issue owing to different serum and growth factor requirements of the two cell types. Existing protocols employ high serum concentrations (up to 10% fetal bovine serum), complex feeder systems and a range of supplemental factors. These approaches are technically demanding and
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2D and 3D in vitro assays to quantify the invasive behavior of glioblastoma stem cells in response to SDF-1α. Biotechniques (IF 1.541) Pub Date : 2020-09-01 Vashendriya Vv Hira,Barbara Breznik,Cornelis Jf Van Noorden,Tamara Lah,Remco J Molenaar
Invasion is a hallmark of cancer and therefore in vitro invasion assays are important tools in cancer research. We aimed to describe in vitro 2D transwell assays and 3D spheroid assays to quantitatively determine the invasive behavior of glioblastoma stem cells in response to the chemoattractant SDF-1α. Matrigel was used as a matrix in both assays. We demonstrated quantitatively that SDF-1α increased
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Sample collection and stabilization from saliva samples for SARS-CoV-2 detection by qPCR. Biotechniques (IF 1.541) Pub Date : 2020-09-01
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Keeping the research spotlight on COVID-19. Biotechniques (IF 1.541) Pub Date : 2020-09-01 Francesca Lake
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Antibody validation for protein expression on tissue slides: a protocol for immunohistochemistry. Biotechniques (IF 1.541) Pub Date : 2020-08-27 Tyler MacNeil,Ioannis A Vathiotis,Sandra Martinez-Morilla,Vesal Yaghoobi,Jon Zugazagoitia,Yuting Liu,David L Rimm
Antibodies play a crucial role in basic research and clinical decision-making. However, there are no standardized algorithms or guidelines to ensure their accuracy and validity. There have been efforts to generate consensus, but, with the exception of clinical labs, antibody validation remains variable in the literature and sometimes in clinical practice. Here we focus on immunohistochemistry, an example
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RPA-PCR couple: an approach to expedite plant diagnostics and overcome PCR inhibitors. Biotechniques (IF 1.541) Pub Date : 2020-08-20 Mustafa Ahmad Munawar,Frank Martin,Anna Toljamo,Harri Kokko,Elina Oksanen
DNA extraction can be lengthy and sometimes ends up with amplification inhibitors. We present the potential of recombinase polymerase amplification (RPA) to replace plant DNA extraction. In our rapid 'RPA-PCR couple' concept, RPA is tuned to slower reaction kinetics to promote amplification of long targets. RPA primers amplify target and some flanking regions directly from simple plant macerates. Then
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A simplified method to produce mRNAs and functional proteins from synthetic double-stranded DNA templates. Biotechniques (IF 1.541) Pub Date : 2020-08-20 John T Tossberg,Tashawna M Esmond,Thomas M Aune
We present a method to synthesize mRNAs from synthetic DNA templates that produce biologically active proteins. To illustrate utility, we constructed five unique synthetic DNA templates, produced mRNAs and demonstrated biologic activity of their translated proteins. Examples include secreted luciferase, enhanced green fluorescence protein, IL-4, and IL-12A and IL-12B to form active IL-12. We propose
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PCR past, present and future. Biotechniques (IF 1.541) Pub Date : 2020-08-20 Hanliang Zhu,Haoqing Zhang,Ying Xu,Soňa Laššáková,Marie Korabečná,Pavel Neužil
PCR has become one of the most valuable techniques currently used in bioscience, diagnostics and forensic science. Here we review the history of PCR development and the technologies that have evolved from the original PCR method. Currently, there are two main areas of PCR utilization in bioscience: high-throughput PCR systems and microfluidics-based PCR devices for point-of-care (POC) applications
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Immunochromatographic detection of MPB64 secreted from active BCG by heating: toward same-day diagnosis of tuberculosis. Biotechniques (IF 1.541) Pub Date : 2019-04-08 Kazunari Nakaishi,Satoshi Watabe,Toshiyuki Kitagawa,Etsuro Ito
We propose a new detection method for a tuberculosis-specific protein, MPB64, obtained from active bacillus Calmette-Guérin (BCG) by heating. When BCG was included in solution at a concentration >2.75 × 104 CFU/ml, our method for collecting MPB64 through heating active BCG combined with an immunochromatographic assay detected active bacilli within 2.5 h. By contrast, a culture test, which is the gold
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Rapid identification of genome-edited mesenchymal stem cell colonies via Cas9. Biotechniques (IF 1.541) Pub Date : 2019-03-29 Wei Jiang,Wei Lian,Jieting Chen,Wenlei Li,Jieyong Huang,Baoyu Lai,Lingyun Li,Zhong Huang,Jianyong Xu
Mesenchymal stem cells (MSCs) have been intensively investigated and widely applied in regenerative medicine and immune modulation. However, their efficacy declines during the aging or disease process. Thus, genome-edited MSCs with over-expression or inhibition of specific genes hold a great deal of promise in terms of their therapeutic application. Here we optimized the direct PCR approach for rapid
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Optimizing leading edge F-actin labeling using multiple actin probes, fixation methods and imaging modalities. Biotechniques (IF 1.541) Pub Date : 2019-3-15 Vera DesMarais,Robert J Eddy,Ved P Sharma,Orrin Stone,John S Condeelis
We systematically evaluated the performance and reliability of several widely used, commercially available actin-filament probes in a highly motile breast adenocarcinoma cell line to optimize the visualization of F-actin-rich dynamic lamellipodia. We evaluated four Phalloidin-fluorophores, two anti-actin antibodies, and three live-cell actin probes in five fixation conditions across three imaging platforms
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Liquid array diagnostics: a novel method for rapid detection of microbial communities in single-tube multiplex reactions. Biotechniques (IF 1.541) Pub Date : 2019-3-15 Pranvera Hiseni,Robert C Wilson,Ola Storrø,Roar Johnsen,Torbjørn Øien,Knut Rudi
We present a novel liquid array diagnostics (LAD) method, which enables rapid and inexpensive detection of microbial markers in a single-tube multiplex reaction. We evaluated LAD both on pure cultures, and on infant gut microbiota for a 15-plex reaction. LAD showed more than 80% accuracy of classification and a detection limit lower than 2% of the Illumina reads per sample. The results on the clinical
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Unlabeled image analysis-based cell viability assay with intracellular movement monitoring. Biotechniques (IF 1.541) Pub Date : 2019-3-15 Kazuhiro Nakagawa,Takuya Kishimoto
The need for technologies to monitor cell health is increasing with advancements in the field of cell therapy and regenerative medicine. In this study, we demonstrated unlabeled optical metabolic imaging of cultured living cells. This imaging technique is based on motion vector analysis with a block-matching algorithm to compare sequential time-lapse images. Motion vector analysis evaluates the movement
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Electrochemical methods for probing DNA damage mechanisms and designing cisplatin-based combination chemotherapy. Biotechniques (IF 1.541) Pub Date : 2019-3-15 Zhi Li,Yael Zilberman,Qing-Bin Lu,Xiaowu Shirley Tang
An electrochemical approach was devised for detecting DNA damage and differentiating two DNA damage mechanisms, which is important to the design of new chemotherapeutics. This approach combined two platforms, based on the detection of base damage and DNA strand cleavage. In this work, our approach was demonstrated for the detection of cisplatin-induced DNA damage and the enhancement effects of two
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Grow your own brain. Biotechniques (IF 1.541) Pub Date : 2019-3-15 Jenny Straiton
Jenny Straiton explores the miniature world of organoids and discusses how these small models are making big changes in the world of neurological research.
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An inexpensive air stream temperature controller and its use to facilitate temperature-controlled behavior in Drosophila. Biotechniques (IF 1.541) Pub Date : 2019-3-15 Ryan Sangston,Jay Hirsh
Controlling the environment of an organism has many biologically relevant applications. Temperature-dependent inducible biological reagents have proven invaluable for elucidating signaling cascades and dissection of neural circuits. Here we develop a simple and affordable system for rapidly changing temperature in a chamber housing adult Drosophila melanogaster. Utilizing flies expressing the temperature-inducible
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Rapid extraction of DNA suitable for NGS workflows from bacterial cultures using the PDQeX. Biotechniques (IF 1.541) Pub Date : 2019-02-28 Jo-Ann L Stanton,Abishek Muralidhar,Christy J Rand,David J Saul
Background: PDQeX is a novel, single-step DNA extraction method that purifies nucleic acid from sample in under 30 min. Materials & Methods: Six bacterial suspensions from species with different cell morphologies and growth optima were made. DNA from half the suspension was purified using PDQeX and the other half using a conventional column purification method. Sequencing and analyses using Ion PGM
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Single-step colony assay with autoinduction of scFv expression for the screening of antibody libraries. Biotechniques (IF 1.541) Pub Date : 2019-02-20 Mieko Kato,Yoshiro Hanyu
We present a simple colony assay method for screening antibody libraries based on autoinduction of antibody fragment expression. This protocol eliminates the need for colony size monitoring and a separate induction step for single-chain Fv (scFv) antibody fragment expression. Here, scFvs are expressed in an automatic and timely fashion during the assay, resulting in high yields of positive clones and
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Idiosyncrasies of thermofluorimetric aptamer binding assays. Biotechniques (IF 1.541) Pub Date : 2019-02-15 Tulsi Ram Damase,Peter B Allen
To explore thermofluorimetric analysis (TFA) in detail, we compared two related aptamers. The first, LINN2, is a DNA aptamer previously selected against EGFR recombinant protein. In this work we selected a second aptamer, KM4, against EGFR-overexpressing A549 cells. The two aptamers were derived from the same pool and bind the same target but behave differently in TFA. Our results suggest four overall
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Improved locus-specific unmethylated controls for MS-HRM analysis derived from 5-aza-2-deoxycytidine-treated DNA. Biotechniques (IF 1.541) Pub Date : 2019-02-14 Helena Čelešnik,Uroš Potočnik
We report two restriction enzyme-based approaches for generating clean locus-specific unmethylated controls for methylation-sensitive high-resolution melting (MS-HRM) analyses. These unmethylated standards are derived from DNA treated with the demethylating agent 5-aza-2-deoxycytidine (5-Aza-dc). By using them, we overcome a limitation of 5-Aza-dc treatment - incomplete demethylation at various genomic
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From Sanger sequencing to genome databases and beyond. Biotechniques (IF 1.541) Pub Date : 2019-2-13 Jenny Straiton,Tristan Free,Abigail Sawyer,Joseph Martin
We look at how next-generation sequencing has advanced research across different disease fields, and the growing importance of open access genomic databases.
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SeqScrub: a web tool for automatic cleaning and annotation of FASTA file headers for bioinformatic applications. Biotechniques (IF 1.541) Pub Date : 2019-06-20 Gabriel Foley,Leander Sützl,Stephlina A D'Cunha,Elizabeth Mj Gillam,Mikael Bodén
Data consistency is necessary for effective bioinformatic analysis. SeqScrub is a web tool that parses and maintains consistent information about protein and DNA sequences in FASTA file format, checks if records are current, and adds taxonomic information by matching identifiers against entries in authoritative biological sequence databases. SeqScrub provides a powerful, yet simple workflow for managing
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