Differential expression under hypoxia in zebrafish
Ontology highlight
ABSTRACT:
ORGANISM(S): Danio rerio
PROVIDER: GSE2069 | GEO | 2004/12/21
SECONDARY ACCESSION(S): PRJNA91323
REPOSITORIES: GEO
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2006-01-05 | GSE3974 | GEO
Project description:Total RNA isolated from 10 individual human cell lines were reverse-transcribed to cDNA, labeled with Cy5 and co-hybridized with Cy3-labeled UHRR onto 43,000-spot cDNA microarrays (Stanford University). The data was analyzed using GeneTraffic software. Approximately 6000-8000 spots out of 43,000 (14-18 %) were flagged on each microarray and excluded from further analysis. Spots with hybridization signals in Cy5 channel higher than 1000 and with Cy5/Cy3 ratio greater than 2 were collected and the number of spots with these characteristics in only one cell line was determined. A reference experiment design type is where all samples are compared to a common reference. Keywords: reference_design
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Project description:RNA from 11 individual mouse cell lines were reverse-transcribed to cDNA, labeled with Cy5 and cohybridized with Cy3-labeled UMRR onto 7,500-spot mouse oligo microarrays (UNC). The data was analyzed using GeneTraffic software. 300-1000 spots out of 8,000 were flagged on each microarray and excluded from further analysis. Spots with hybridization signals in Cy5 channel higher than 1000 and with Cy5/Cy3 ratio greater than 2 were collected and the number of spots with these characteristics on only one microarray was determined.
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Project description:Total RNA isolated from 10 individual human cell lines were reverse-transcribed to cDNA, labeled with Cy5 and co-hybridized with Cy3-labeled UHRR onto 43,000-spot cDNA microarrays (Stanford University). The data was analyzed using GeneTraffic software. Approximately 6000-8000 spots out of 43,000 (14-18 %) were flagged on each microarray and excluded from further analysis. Spots with hybridization signals in Cy5 channel higher than 1000 and with Cy5/Cy3 ratio greater than 2 were collected and the number of spots with these characteristics in only one cell line was determined.
2005-11-01 | E-SMDB-2651 | biostudies-arrayexpress
Project description:RNA from 11 individual mouse cell lines were reverse-transcribed to cDNA, labeled with Cy5 and cohybridized with Cy3-labeled UMRR onto 7,500-spot mouse oligo microarrays (UNC). The data was analyzed using GeneTraffic software. 300-1000 spots out of 8,000 were flagged on each microarray and excluded from further analysis. Spots with hybridization signals in Cy5 channel higher than 1000 and with Cy5/Cy3 ratio greater than 2 were collected and the number of spots with these characteristics on only one microarray was determined. A reference experiment design type is where all samples are compared to a common reference. Computed
2006-01-04 | E-GEOD-3974 | biostudies-arrayexpress
Project description:The experiment was designed to enable validation of pre-processing and test algorithms. The in-house produced cDNA-array contains 44 clones: 19 clones from mice, 4 clones from Pine (involved in photosynthesis) and 21 artificial clones from the Lucidea Universal ScoreCard (Amersham Bioscienses), where each clone was printed 480 times in 48 identically designed sub-grids. The experiment contains eight arrays with identical experimental design. Total RNA from murine cell line was divided in two samples; the reference sample was labeled with the fluorophore Cy5 and spiked with the Lucidea Universal ScoreCard reference reaction, the test sample was labeled with Cy3 and spiked with the Lucidea Universal ScoreCard test reaction. The concentrations of the Lucidea reactions are known and consequently so are the true ratios between the reference and test channels. Approximately 40% of the artificial genes were differentially expressed. The particular design of the experiment makes the data suitable for validating algorithms for pre-processing and tests for identifying differentially expressed genes. - The 80.I.1 normalization algorithm : all spots flagged as not found during image analysis considered missing values (complete filtration). Print-tip MA-loess dye normalization based on the calibration clones was applied to the raw data and the B-statistic was calculated. - The 80.II.1 normalization algorithm : all spots flagged as not found during image analysis considered missing values (complete filtration). Local background correction was applied and all spots with negative values were excluded. Print-tip MA-loess dye normalization based on the calibration clones was applied to the background corrected data and the B-statistic was calculated. - The 80.II.64 normalization algorithm : all spots flagged as not found during image analysis considered missing values (complete filtration). Local background correction was applied, negative values were excluded and all spots with a value below 64 were set to 64 (censored). Print-tip MA-loess dye normalization based on the calibration clones was applied to the background corrected data and the B-statistic was calculated. - The 80.V.1 normalization algorithm : The intensities of all spots flagged not found were treated as missing values during normalization, but prior to calculating test-statistics the spot's log-ratios were set to zero. In the special case when all arrays generated not-found spots, the gene was removed from the experiment (Partial filtration). Local background correction was applied and all negative values were considered missing values. Print-tip MA-loess dye normalization based on the calibration clones was applied to the background corrected data and the B-statistic was calculated.
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Project description:Berberine is a natural isoquinoline alkaloid found in Chinese medicinal herbs which is active against a variety of microbial infections. To examine the potential effects of berberine on Shigella flexneri, a whole-genome DNA microarray was constructed and transcriptome analysis of the cellular responses of S.flexneri when exposed to Berberine Chloride (BC) was performed. When cultures were grown to early exponential growth phase, drug was added. Meanwhile, DMSO solution without BC was added to control cultures to the same final concentration. At 30 min after treatment, samples were collected and washed twice with phosphate buffered saline at 25°C for subsequent RNA isolation. To prepare biological replicates for RNA isolation, each experiment was independently performed three times. After drug treatment, total RNA was extracted using SV RNA Isolation System (Promega). Reverse transcription of 20 ug RNA from each sample was performed with Superscript II system (Invitrogen) to prepare cDNA. According to the manufacturer's instructions, the cDNA was labeled with incorporation of fluorescent dyes (Amersham). Cy3-dCTP monofunctional dye was selected for control cDNA samples and Cy5-dCTP was used for drug-treated samples. Each pair of labeled cDNA was mixed and dried by vacuum centrifugation. The pairs of the labeled cDNA samples were hybridized to the DNA microarrays following the protocol available at http://www.ifr.ac.uk/safety/microarrays/. The slides were scanned by using a GenePix 4100A scanner. Fluorescent spots and local background intensities were quantified using GenePix Pro 6.0 software (Axon). Signal intensities were corrected by subtracting the local background value. The data set was filtered so that spots flagged as "not found," "bad," and "empty" were excluded from further analysis. Moreover, spots either with signal-to-noise ratio below the detection limit of 3 or containing less than 55% of pixels two standard deviations above background in both channels were discarded from the data set. Lowess normalization was performed with the fluorescent signal ratios (Cy5/Cy3) using MIDAS software (http://www.tigr.org/software/tm4) with a 0.33 smooth parameter.
2012-03-10 | E-GEOD-16714 | biostudies-arrayexpress
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