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The Genomics Platform proposes a complete service:
• advice on the selection of the approach and the design of the experiment
• advice on the preparation of the samples
• experiment
• data analysis and storage
Note: data analysis for genotyping studies is not currently provided.
The Platform is fully equipped with bench space to welcome collaborators.
Collaborators appoint a person actually performing the experiments under full supervision of the Platform staff,
which participates in your experiment and introduces you to the Platforms equipment.
Alternative forms of service can be envisaged upon request.
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Guaranty of confidentiality
The Genomics Platform will consider as strictly confidential, and will not release any information, document or data related to a project, of which the Genomics Platform will have had knowledge during the performance of the service, without prior consent of the clients.
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Planning an experiment
Collaborators are accepted on a first-come-first-served basis. We strongly encourage them to contact us and interact with us as much as required to discuss the planning and the design of any experiment to be performed on the Platform.
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Collaborators are asked to fill an agreement form that contains information about the experiment, the type of arrays, the service that the Platform provides, and an estimate of the cost of the experiment planned.
The agreement form is available upon request. ›› E-mail
Collaborators are strongly advised to consult our guidelines where we describe recommendations in order to maximize the rate of success of a microarray experiment.
Workflow of an Affymetrix and Illumina gene expression experiment
- Design of the experiment experiment (this initial step requires discussion with the manager of the platform)
- RNA sample preparation (performed by the collaborator in his/her own laboratory; suggestions regarding extraction methods are available upon request)
- Control of RNA quality on the 2100 Bioanalyzer
- Preparation of targets
- Hybridization of some targets on Test 3 arrays for quality control (applies only to Affymetrix)
- Hybridization on GeneChips or BeadArrays
- Data analysis and data mining
We currently propose the following protocols for targets preparation.
For Affymetrix GeneChips
- For RNA quantities ≥ 1 µg total RNA: the classical amplification, which includes cDNA synthesis using oligo-dT-T7 primer, followed by in vitro transcription (one-cycle labeling).
- For RNA quantities < 1 µg, down to 100 ng of total RNA: the small scale protocol, where all steps in the procedure described above are performed twice (two-cycle labeling).
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See schematic representations:
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For Illumina BeadArrays
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For RNA quantities ≥ 100 ng of total RNA:
the Illumina® TotalPrep™ RNA Amplification Kit from Ambion, ABI (details on Ambion website),
which includes cDNA synthesis using oligo-dT-T7 primer, followed by in vitro transcription (one-cycle labeling).
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The Platform proposes the Ovation™ Biotin System from NuGEN
(details on NuGEN website) as an alternative amplification method for samples available in very low quantities such as those obtained following FACS-based cell sorting or Laser Capture Microdissection (LCM).
Ordering reagents, GeneChips and BeadArrays
To guaranty homogeneity and reproducibility, all reagents (including GeneChips and BeadArrays) are ordered by the Platform.
Data analysis
For the initial treatment of raw data and statistical analysis, we currently use the following solutions.
For Affymetrix GeneChips
• The GCOS or Expression Console software of Affymetrix; data are further compiled using a program developed in MatLab or in R.
• RMA (Robust Multichip Average) (see RMAExpress web page, and Irizzary et al, 2003 - PDF; 16 pages, 960 KB).
For Illumina BeadArrays
BeadStudio software of Illumina; data are further compiled using a program developed in MatLab or in R.
Additional data analysis and data visualization are performed with GeneSpring ( Agilent Technologies).
Data interpretation
The Plateform provides access to GeneGo to analyze and build hypothesis on data generated by global genomics approaches like microarrays.
The GeneGo data mining tools and databases help to capture and define the underlying biology behind different types of high-throughput experimental data.
The Platform is a GeneGo recognized Center of Excellence (COE).
Data storage
In the frame of the Swiss Array Consortium, we have collaborated with Dr Mike Primig (formerly in Basel, currently at the University of Rennes, France) to develop MIMAS, a data warehouse to hold a vast amount of raw microarray data described in a complete and MIAME-compliant manner ( see MIMAS web pages and Hermida et al., 2006).
MIMAS is currently hosted by Vital IT. In order to guaranty confidentiality, access to the data stored in MIMAS will be restricted by login and password.
Publications
The Genomics Platform supports the MIAME standard for microarray experiment. Please consult these guidelines, based on the document called Minimum Information About a Microarray Experiment developed by the Microarray Gene Expression Data society.
| Real-time quantitative PCR |
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Workflow for qRT-PCR
- Selection of genes of interest
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Design of amplicons and TaqMan® probes (when selected)
Depending on the application and the specificity of the projects (number of amplicons to measure, number of samples),
amplicons, primers and TaqMan® probes are designed with extremely high success rates using:
• the software Primer Express Version 2.0 (ABI)
• the Roche Universal Probe Library system (Roche)
Alternatively, validated designs can be directly ordered from ABI.
- RNA sample preparation (performed by the collaborator in his/her own laboratory)
- Control of RNA quality on the 2100 Bioanalyzer
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cDNA synthesis
When very low amount of starting material are available, pre-amplification is performed using the NuGEN WT-Ovation™ kit (details on NuGEN website).
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Reaction for qPCR assembly
Assembly is performed in 384-well plates with a pipetting robot Biomek 2000 from Beckman
(details on Beckman website) or Freedom EVO 150 from Tecan (details on Tecan website).
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Data analysis and fold-change evaluation
We use multiple normalization genes (so called “house keeping” genes) for data normalization. This approach provides much more accurate measures of fold-changes compared to the classical use of single normalization gene.
The selection of adequate normalization genes is performed using the application geNorm (Vandesompele et al., 2002 - PDF; 12 pages, 141 KB).
geNorm is implemented into our Excel macro. Subsequent data analysis (raw data QC, averaging of measures, normalization, computing of normalized data, fold-changes calculation and graphical display) are all covered by our Excel macro, available upon request.
| Ultra high throughput sequencing |
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Workflow of sequencing experiment
We strongly encourage collaborators to contact the Platform to discuss the planning and design of sequencing experiments before samples preparation.
For precise information regarding the quantity of samples (RNA or DNA), as well as pricing, please contact us.
Samples
Samples can be quality controlled (integrity and quantity) on the Platform using:
Fragmentation of genomic DNA
The Platform is equipped with a Covaris S instrument for efficient and reproducible shearing of DNA using Adaptive Focused Acoustics (AFA™) ( details on Covaris website).
Library preparation
The Platform proposes two modes of operation.
- Collaborators can produce their libraries, following advice of the Platform.
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The personnel of the Platform prepares the library.
Our classical workflow includes:
- preparation of single read or paired-end libraries using Illumina reagents
- size fractionation of the library on E-Gels® SizeSelect™ 2% Agarose
- quality control of the library (including Topo cloning and Sanger sequencing of a few clones)
Sequencing
Depending upon requirement for the project, sequencing of 38, 54, 76 or 105 bases, single read or paired-end, will be performed.
Data analysis
The Platform currently supports limited data analysis:
- quality control of the sequencing
- alignment of the reads onto a reference genome using Illumina pipe line (ELAND)
Data storage and data analysis are performed in close collaboration and thanks to the support of Vital-IT.
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