Search results for "DNA microarray"

SiPM as miniaturised optical biosensor for DNA-microarray applications

2015

A miniaturized optical biosensor for low-level fluorescence emitted by DNA strands labelled with CY5 is showed. Aim of this work is to demonstrate that a Si-based photodetector, having a low noise and a high sensitivity, can replace traditional detection systems in DNA-microarray applications. The photodetector used is a photomultiplier (SiPM), with 25 pixels. It exhibits a higher sensitivity than commercial optical readers and we experimentally found a detection limit for spotted dried samples of ∼1 nM. We measured the fluorescence signal in different operating conditions (angle of analysis, fluorophores concentrations, solution volumes and support). Once fixed the angle of analysis, for s…

Configurable low-cost plotter device for fabrication of multi-color sub-cellular scale microarrays.

2014

We report on the construction and operation of a low-cost plotter for fabrication of microarrays for multiplexed single-cell analyses. The printing head consists of polymeric pyramidal pens mounted on a rotation stage installed on an aluminium frame. This construction enables printing of microarrays onto glass substrates mounted on a tilt stage, controlled by a Lab-View operated user interface. The plotter can be assembled by typical academic workshops from components of less than 15 000 Euro. The functionality of the instrument is demonstrated by printing DNA microarrays on the area of 0.5 squared centimeters using up to three different oligonucleotides. Typical feature sizes are 5 μm diam…

Plaid model for microarray data: an enhancement of the pruning step

2010

Microarrays have become a standard tool for studying gene functions. For example, we can investigate if a subset of genes shows a coherent expression pattern under different conditions. The plaid model, a model-based biclustering method, can be used to incorporate the addiction structure used for the microarray experiment. In this paper we describe an enhancement for the plaid model algorithm based on the theory of the false discovery rate.

Estimating the extent of horizontal gene transfer in metagenomic sequences

2008

Abstract Background Although the extent of horizontal gene transfer (HGT) in complete genomes has been widely studied, its influence in the evolution of natural communities of prokaryotes remains unknown. The availability of metagenomic sequences allows us to address the study of global patterns of prokaryotic evolution in samples from natural communities. However, the methods that have been commonly used for the study of HGT are not suitable for metagenomic samples. Therefore it is important to develop new methods or to adapt existing ones to be used with metagenomic sequences. Results We have created two different methods that are suitable for the study of HGT in metagenomic samples. The …

MGFM: a novel tool for detection of tissue and cell specific marker genes from microarray gene expression data

2015

Background Identification of marker genes associated with a specific tissue/cell type is a fundamental challenge in genetic and cell research. Marker genes are of great importance for determining cell identity, and for understanding tissue specific gene function and the molecular mechanisms underlying complex diseases. Results We have developed a new bioinformatics tool called MGFM (Marker Gene Finder in Microarray data) to predict marker genes from microarray gene expression data. Marker genes are identified through the grouping of samples of the same type with similar marker gene expression levels. We verified our approach using two microarray data sets from the NCBI’s Gene Expression Omn…

Diversity Arrays Technology (DArT) for Pan-genomic Evolutionary Studies of Non-model Organisms

2007

BackgroundHigh-throughput tools for pan-genomic study, especially the DNA microarray platform, have sparked a remarkable increase in data production and enabled a shift in the scale at which biological investigation is possible. The use of microarrays to examine evolutionary relationships and processes, however, is predominantly restricted to model or near-model organisms.Methodology/principal findingsThis study explores the utility of Diversity Arrays Technology (DArT) in evolutionary studies of non-model organisms. DArT is a hybridization-based genotyping method that uses microarray technology to identify and type DNA polymorphism. Theoretically applicable to any organism (even one for wh…

Application of Nanogen microarray technology for forensic SNP analysis

2006

Abstract The NanoChip® Molecular Biology Workstation using electronic microarrays is an approach for rapid and high throughput analysis of SNPs. This instrument is fully automated and uses a microchip for electronic addressing of capture probes to specific array sites followed by electronic hybridisation of the single stranded PCR products, and passive hybridisation of fluorescently labelled reporter probes. Discrimination is achieved by applying thermal stringency to denature the mismatched reporters. 48 SNP assays have been designed using the ‘capture down’ assay which applies a thermal ‘touch down’ strategy to obtain the best reporter probe discrimination.

2013

Abstract Background The cumulus cells (CCs) enveloping antral and ovulated oocytes have been regarded as putative source of non-invasive markers of the oocyte developmental competence. A number of studies have indeed observed a correlation between CCs gene expression, embryo quality, and final pregnancy outcome. Here, we isolated CCs from antral mouse oocytes of known developmental incompetence (NSN-CCs) or competence (SN-CCs) and compared their transcriptomes with the aim of identifying distinct marker transcripts. Results Global gene expression analysis highlighted that both types of CCs share similar transcriptomes, with the exception of 422 genes, 97.6% of which were down-regulated in N…

Genomic response programs of Saccharomyces cerevisiae following protoplasting and regeneration.

2007

Abstract Global transcription profiling during regeneration of Saccharomyces cerevisiae protoplasts was explored. DNA microarrays measured the expression of 6388 genes and wall removal resulted initially in over-expression of 861 genes that decayed later on, a behaviour expected from a transient stress response. Kinetics of expression divided the genes into 25 clusters. Transcription of the genes from clusters 14–25 was initially up-regulated, suggesting that the grouped genes permitted cell adaptation to the removal of the wall. Clustering of genes involved in “wall structure and biosynthesis” showed that most of them had initially low levels of expression that increased along the process.…

Molecular biology approaches utilized in preimplantation genetics: real-time PCR, microarrays, next-generation sequencing, karyomapping, and others

2020

Abstract Over the past few decades the development of new molecular technologies has revolutionized diagnosis in the reproductive medicine field, with the evaluation of the two main factors involved in a successful pregnancy: the embryo and the endometrium. The detection of genetically abnormal embryos, as well as the identification of an optimum endometrium using transcriptomics have become a priority in assisted reproductive treatments to increase pregnancy rates. This chapter provides an overview of the molecular techniques currently employed in assisted reproduction for embryo evaluation such as preimplantation genetic testing karyotyping, fluorescence in situ hybridization, polymerase …