Effects of ethanol on poly IC gene induction
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE1308 | GEO | 2004/04/15
SECONDARY ACCESSION(S): PRJNA89903
REPOSITORIES: GEO
Similar Datasets
Project description:Experiment on the effects of ethanol (acute oral) on induction of genes by polyinosinic polycytidylic acid (poly IC). Microarray methodology follows: cDNA for each sample was synthesized from 8.5 µg total RNA using a Superscript cDNA Synthesis Kit (Invitrogen, Carlsbad, CA) in combination with a T7-(dT)24 primer. Following phenol-chloroform extraction of the cDNA, biotinylated cRNA was transcribed in vitro using the BioArray HighYield RNA Transcript Labeling Kit (ENZO Biochem, New York, NY) and purified using the RNeasy Mini Kit (Qiagen, Valencia, CA). Twenty micrograms of purified cRNA was fragmented by incubation in fragmentation buffer (200 mM Tris-acetate, pH 8.1, 500 mM potassium acetate, 150 mM magnesium acetate) at 94°C for 35 minutes and chilled on ice. Fifteen micrograms of fragmented biotin-labeled cRNA was hybridized to the Murine Genome U74Av2 Array (Affymetrix, Santa Clara, CA), interrogating a total of 12,488 murine gene cDNA probes, for 16 hr at 45°C with constant rotation (60 rpm). The arrays were washed and then stained for 10 min at 25°C with 10 µg/mL streptavidin-R phycoerythrin (Vector Laboratories, Burlingame, CA) followed by 3 µg/mL biotinylated goat anti-streptavidin antibody (Vector Laboratories) for 10 minutes at 25°C. Arrays were then stained once again with streptavidin-R phycoerythrin for 10 min at 25°C. After washing and staining, the arrays were scanned using an Agilent GeneArray Scanner (Agilent Technologies) at 570 nm. Pixel intensities were measured, expression signals were analyzed and features extracted using a commercial software package (Microarray Suite ver 5.0, Affymetrix). Data mining and statistical analyses were performed with Data Mining Tool ver 3.0 (Affymetrix) algorithms. Arrays were globally scaled to a target intensity value of 2,500 in order to compare individual experiments. The absolute call (present, marginal, absent) of 12,488 gene expressions in each sample, as well as the direction of change, and fold change of gene expressions between samples were identified using the above-mentioned software.
2008-06-12 | E-GEOD-1308 | biostudies-arrayexpress
Project description:Endothelial cells comprise a key component of the inflammatory response. HUVEC (human umbilical vein endothelial cells) were stimulated with interleukin-1 for 0, 0.5, 1, 2.5 and 6 hours, and analyzed using Affymetrix U133A microarrays, in order to obtain a comprehensive overview of the immediate early to early gene expression profiles. HUVEC were isolated and cultured on gelatine-coated cell culture dishes in M199 medium supplemented with 20% FCS, antibiotics, ECGS (endothelial cell growth supplement) and Heparin as described by Zhang et al., Blood 1996;88:3880-3886. HUVEC were stimulated with 100 U/ml human IL-1 (Biosource) for various periods of time, and total RNA isolated using the RNeasy kit (Qiagen) according to the manufacturer's instructions. Hybridization to one set of human U133A GeneChips (Affymetrix, Santa Clara, CA) and scanning of the arrays was carried out according to manufacturer’s protocols (https://www.affymetrix.com). Briefly, 5 µg of total RNA was used to generate double-stranded cDNA by reverse transcription using a cDNA synthesis kit (Superscript Choice System; Life Technologies, Inc., Rockville, MD) that uses an oligo(dT)24 primer containing a T7 RNA polymerase promoter 3' to the polyT (Geneset, La Jolla, CA), followed by second-strand synthesis. Labeled cRNA was prepared from the double-stranded cDNA by in vitro transcription using T7 RNA polymerase in the presence of biotin-11-CTP and biotin-16-UTP (Enzo, Farmington, NY). The labeled cRNA was purified over RNeasy columns (Qiagen, Valencia, CA). Fifteen µg of cRNA was fragmented at 94°C for 35 minutes in 40 mmol/L of Tris-acetate, pH 8.1, 100 mmol/L of potassium acetate, and 30 mmol/L of magnesium acetate. The cRNA was then used to prepare 300 µl of hybridization cocktail (100 mmol/L MES, 1 mol/L NaCl, 20 mmol/L ethylenediaminetetraacetic acid, 0.01% Tween 20) containing 0.1 mg/ml of herring sperm DNA (Promega, Madison, WI) and 500 µg/ml of acetylated bovine serum albumin (Life Technologies, Inc.). Before hybridization, the cocktails were heated to 94°C for 5 minutes, equilibrated at 45°C for 5 minutes, and then clarified by centrifugation (16,000 x g) at room temperature for 5 minutes. Aliquots of this hybridization cocktail containing 15 µg of fragmented cRNA were hybridized to HU133A arrays (Affymetrix, Santa Clara, CA) at 45°C for 16 hours in a rotisserie oven at 60 rpm. The arrays were washed using non-stringent buffer (6xSSPE: 0.9 M sodium chloride, 0.06 M sodium phosphate, 6 mM EDTA pH 7.4) at 25°C, followed by stringent buffer (100 mmol/L MES, pH 6.7, 0.1 mol/L NaCl, 0.01% Tween 20) at 50°C. The arrays were stained with streptavidin-phycoerythrin (Molecular Probes, Eugene, OR), washed with 6xSSPE, incubated with biotinylated anti-streptavidin IgG, stained again with streptavidin-phycoerythrin, and washed again with 6xSSPE. The arrays were scanned using the GeneArray scanner (Affymetrix). Image analysis was performed with GeneChip software (Affymetrix, MAS 5.0). Normalization was performed by global scaling, with the arrays scaled to an average intensity of 500. Keywords: time-course
2004-07-20 | GSE973 | GEO
Project description:Peripheral blood mononuclear cells were isolated 0, 30 min, 6 h, 24 h, and 7 day after intravenous endotoxin challenge using cell preparation tubes (Vacutainer® CPT). The PBMC layer was lysed with RLT buffer, homogenized, and then stored at 80°C. Total RNA was extracted as per RNeasy Midi protocol (Qiagen). Double stranded cDNA was synthesized from total RNA (5 to 20 µg) using 7-d(T)24 primer and SuperScript Double-Stranded cDNA Synthesis Kit and purified by phase lock gel-phenol/chloroform extraction followed by ethanol precipitation. Biotin-labeled cRNA was prepared by in vitro transcription using HighYield RNA Transcript Labeling Kit followed by fragmentation with 5X fragmentation buffer. Fragmented cRNA (10 µg) was hybridized to Affymetrix Hu95Av2 oligonucleotide probe arrays for 16 h at 45?C. After removal of hybridization fluid, the arrays were washed, stained with streptavidin phycoerythrin (SAPE), and signal amplified by anti-streptavidin antibody using Affymetrix Fluidics Station 400. Probe set signals were measured using Agilent GeneArray Scanner (Affymetrix, Santa Clara, CA).
2007-12-19 | E-GEOD-3026 | biostudies-arrayexpress
Project description:Endothelial cells comprise a key component of the inflammatory response. HUVEC (human umbilical vein endothelial cells) were stimulated with interleukin-1 for 0, 0.5, 1, 2.5 and 6 hours, and analyzed using Affymetrix U133A microarrays, in order to obtain a comprehensive overview of the immediate early to early gene expression profiles. HUVEC were isolated and cultured on gelatine-coated cell culture dishes in M199 medium supplemented with 20% FCS, antibiotics, ECGS (endothelial cell growth supplement) and Heparin as described by Zhang et al., Blood 1996;88:3880-3886. HUVEC were stimulated with 100 U/ml human IL-1 (Biosource) for various periods of time, and total RNA isolated using the RNeasy kit (Qiagen) according to the manufacturer's instructions. Hybridization to one set of human U133A GeneChips (Affymetrix, Santa Clara, CA) and scanning of the arrays was carried out according to manufacturerâs protocols (https://www.affymetrix.com). Briefly, 5 µg of total RNA was used to generate double-stranded cDNA by reverse transcription using a cDNA synthesis kit (Superscript Choice System; Life Technologies, Inc., Rockville, MD) that uses an oligo(dT)24 primer containing a T7 RNA polymerase promoter 3' to the polyT (Geneset, La Jolla, CA), followed by second-strand synthesis. Labeled cRNA was prepared from the double-stranded cDNA by in vitro transcription using T7 RNA polymerase in the presence of biotin-11-CTP and biotin-16-UTP (Enzo, Farmington, NY). The labeled cRNA was purified over RNeasy columns (Qiagen, Valencia, CA). Fifteen µg of cRNA was fragmented at 94°C for 35 minutes in 40 mmol/L of Tris-acetate, pH 8.1, 100 mmol/L of potassium acetate, and 30 mmol/L of magnesium acetate. The cRNA was then used to prepare 300 µl of hybridization cocktail (100 mmol/L MES, 1 mol/L NaCl, 20 mmol/L ethylenediaminetetraacetic acid, 0.01% Tween 20) containing 0.1 mg/ml of herring sperm DNA (Promega, Madison, WI) and 500 µg/ml of acetylated bovine serum albumin (Life Technologies, Inc.). Before hybridization, the cocktails were heated to 94°C for 5 minutes, equilibrated at 45°C for 5 minutes, and then clarified by centrifugation (16,000 x g) at room temperature for 5 minutes. Aliquots of this hybridization cocktail containing 15 µg of fragmented cRNA were hybridized to HU133A arrays (Affymetrix, Santa Clara, CA) at 45°C for 16 hours in a rotisserie oven at 60 rpm. The arrays were washed using non-stringent buffer (6xSSPE: 0.9 M sodium chloride, 0.06 M sodium phosphate, 6 mM EDTA pH 7.4) at 25°C, followed by stringent buffer (100 mmol/L MES, pH 6.7, 0.1 mol/L NaCl, 0.01% Tween 20) at 50°C. The arrays were stained with streptavidin-phycoerythrin (Molecular Probes, Eugene, OR), washed with 6xSSPE, incubated with biotinylated anti-streptavidin IgG, stained again with streptavidin-phycoerythrin, and washed again with 6xSSPE. The arrays were scanned using the GeneArray scanner (Affymetrix). Image analysis was performed with GeneChip software (Affymetrix, MAS 5.0). Normalization was performed by global scaling, with the arrays scaled to an average intensity of 500.
2008-06-16 | E-GEOD-973 | biostudies-arrayexpress
Project description:A total of 20 KYSE human esophageal squamous cell carcinoma cell lines (KYSE-30, -140, -150, -170, -180, -200, -220, -350, -410, -450, -510, -520, -590, -770, -850, -890, -1170, -1190, -1250, and -2270) were kindly provided by Dr. Y. Shimada (Kyoto University, Kyoto, Japan). The KYSE cell lines were cultured in RPMI 1640 medium (Life Technologies, Inc., Grand Island, NY) containing 10% heat-inactivated fetal bovine serum (FBS; BioWhittaker, Verviers, Belgium) in a humidified atmosphere of 5% CO2 and maintained in continuous exponential growth by passage every 3 days. The exponentially growing cultured cells (2 x 10^6) were collected after two-washings with PBS. Total RNA was prepared from the frozen cell pellets using QIAGEN RNeasy mini kit (QIAGEN, Inc., Valencia, CA). The quality of the RNA was checked using Agilent Technologies 2100 Bioanalyzer (Agilent, Palo Alto, CA). CodeLink Expression Bioarray System (Amersham Bioscience, Tokyo, Japan) was used according to the manufacturer’s protocol. Briefly, first-strand cDNA was generated from 1 µg of total RNA for each cell line using reverse transcriptase and a T7 primer, and then second-strand cDNA was produced using DNA polymerase mix and RNase H. cRNA was generated via an in vitro transcription reacrion using T7 RNA polymerase and biotin-11-UTP (Perkin Elmer, Boston, MA). After quantified by spectrometry and qualified using Agilent Technologies 2100 Bioanalyzer (Agilent), 10 µg of cRNA was fragmented and hybridized to a Uniset Human 20K I Bioarray containing 19,981 human probes with 108 positive and 300 negative bacterial control probes. After hybridization, the arrays were rinsed and labeled with Streptavidin-Cy5, scanned using Agilent DNA Microarray Scanner (Agilent), then analyzed with CodeLink Expression Analysis Software ver.2.3. Expression levels were normalized to the median expression value of the whole array spots except for the bacterial controls. Keywords: parallel sample
2005-12-31 | GSE2447 | GEO
Project description:Rationale: During excessive pressure or overload, cardiac cells are subjected to increased mechanical stress. We investigate how the stress response of cardiac cells to mechanical stress can be compared to genotoxic stresses induced by DNA damaging agents. Methods: Cultures enriched for cardiomyocytes and cultures of fibroblasts were derived from ventricles of neonatal rat hearts. In three independent experiments, both cell cultures were subjected to mechanical stress (cyclic stretch at 60 cycles/min), UV irradiation (10 J/m2), or X-rays (8.5 Gy). Cells were harvested 24 h. after (the onset of) treatment. Total RNA was isolated using an RNeasy® kit (Qiagen). Single stranded cDNA was synthesized from RNA from myocyte-enriched populations (10-14 microgram) and populations of fibroblasts (7.5-14 microgram), using Superscript II reverse transcriptase and T7-oligo(dT)24 primers at 42ºC for 1 h. Double stranded cDNA was obtained by using DNA ligase, DNA polymerase I and RNAse H at 16ºC for 2 h, followed by T4 DNA polymerase at 16ºC for 5 min. cRNA was synthesized from cDNA using the BioArray HighYield® RNA transcript labeling kit (Enzo) in the presence of biotin-labeled CTP and UTP. cRNA was fragmented in a buffer containing 40 mM Tris-acetate (pH 8.1), 100 mM KAc and 30 mM MgAc, at 94ºC for 35 min. Fragmented cRNA was hybridized to GeneChip RG-U34A arrays (Affymetrix) at 45ºC for 16 h. Arrays were washed and incubated with a streptavidin-phycoerythrin complex. Fluorescent signals were determined with a GeneChip scanner. Keywords: other
2004-12-03 | GSE2032 | GEO
Project description:We have used commercially available oligonucleotide arrays to measure the relative expression levels of >10,000 genes and ESTs. Recent evidence suggested certain advantages of performing such expression experiments on two or more different platforms of oligonucleotide arrays. Here we have used two oligonucleotide platforms, MG U74Av2.0 arrays from Affymetrix and CodeLink UniSet1 from GE Healthcare, to assess whole brain gene expression patterns in naive C57BL/6 and DBA/2J mice. C57BL/6J (n = 5) and DBA/2J (n = 4) male mice, 25-30 g body weight, were obtained from Jackson Laboratories. Animals were group-housed and quickly sacrificed by CO2 exposure according to a protocol approved by the UCHSC IACUC. Brains were rapidly removed and stored at -80oC until use. Whole brain was homogenized in lysis buffer using a Polytron, and total RNA was isolated using the RNeasy Midi Kit (Qiagen) following the protocol supplied by the manufacturer. An additional clean-up of total RNA was carried out using the RNeasy Mini Kit (Qiagen). Using the protocol supplied by the manufacturer, double-stranded cDNA was synthesized from the total RNA (4 ug of total RNA from an individual mouse brain was used for each array) and was used to obtain biotin-labeled cRNA by an in vitro transcription reaction. Biotin-labeled cRNA was recovered using the RNeasy kit. Biotin-labeled cRNA from each mouse was then fragmented and hybridized with two separate (duplicate) CodeLink BioArrays. The average of the gene expression intensity values for each probe set from these technical replicates was used for data analysis. The BioArrays were subsequently stained for 30 min with Cy5-Streptavidin and washed prior to scanning. For MG U74Av2 arrays,double-stranded cDNA was synthesized from 5 ug of total RNA, using the protocol supplied by the manufacturer, and used to obtain biotin-labeled cRNA by an in vitro transcription reaction. Biotin-labeled cRNA was then fragmented and the quality of the fragmented cRNA was assessed using Test2 chips prior to hybridization with the Affymetrix arrays. Hybridization of the cRNA with the Affymetrix arrays was carried out according to the manufacturer's protocol. The arrays were stained with streptavidin-phycoerythrin conjugate and scanned by a GeneArray scanner. Keywords: other
2006-04-05 | GSE2502 | GEO
Project description:Identification of new and unpredicted full length Arabidopsis genes. Examination of cRNA prepared from Arabidopsis thaliana ecotype Columbia light grown 7-day old seedlings, light grown 7-day old seedlings treated at 4 degrees C for 24hrs, and etiolated 7-day old seedlings using pilot genome tiling arrays. Total RNA was isolated from seedlings with the TRIzol reagent procedure of Invitrogen, then poly(A)+ RNA was purified with Qiagen oligotex. One microgram poly(A)+ RNA was converted into ds-cDNA using T7-oligo(dT) primers. Biotin-labeled cRNA was generated by in vitro transcription reactions using ENZO labeling kit, fragmented and then 20 micrograms of fragmented cRNA were hybridized to the arrays according to Affymetrix instructions. Keywords: other
2003-10-30 | GSE604 | GEO
Project description:TGF-beta1 is a pleiotropic cytokine that regulates multiple cellular functions including cell proliferation, differentiation, and apoptosis. It has been identified as one of the mediators of renal hypertrophy and accumulation of extracellular matrix proteins in the diabetic glomerular mesangium. Previous results from our and other laboratories indicate that TGF-beta1 mediates some of the effects of high glucose and glucosamine on extracellular matrix gene expression in mesangial cells. The global regulatory mechanism(s), however, still remains to be understood. In this study, we have utilized an in vitro model of mouse mesangial cells (MES-13) to investigate the genetic effects of TGF-beta1 on global patterns of gene expression, transcriptome and signaling networks. A total number of 179 genes are regulated by TGF-beta1 in MES-13 cells at 2.0-fold, which cover across 44 physiological processes, 31 metabolic functions, and 11 major signaling pathways. We observed that several genes regulated by high glucose and glucosamine are also targeted by TGF-beta1 in MES-13 cells such as thioredoxin interacting protein, glutathione S-transferase theta 1, selenium binding protein 1, inhibitor of DNA binding 2, and plasminogen activator inhibitor-1. The results of this study further support the hypothesis that some effects of high glucose and glucosamine on mesangial gene expression are mediated by TGF-beta1. The identification of these common genes will help us to investigate further their roles in the development and progression of diabetic kidney disease. Cell culture: Stable murine mesangial (MES-13) cells transformed with non-capsid-forming SV-40 virus were obtained from the ATCC, Manassas, VA. These cells display a differentiated mesangial cell phenotype including the typical spindle-like appearance, positive staining for vimentin and desmin, and contraction in response to ANG II and expression of AT1 receptor. The cells were maintained in DMEM and F-12 Nutrient Mixture (Ham's) (4:1 ratio) (GIBCO BRL, Gaithersburg, MD) containing a normal D-glucose concentration of 5.5 mmol/L, 2% FCS, 100 µg/ml streptomycin, 100 U/ml penicillin, and 2 mmol/L glutamine (26). The cells were incubated in a humidified incubator of 5% CO2 at 37 °C and routinely passaged at confluence every 3 days by trypsinization using 10-cm culture dishes. Approximately 50% confluent monolayers were starved in the above medium without FCS for 1 day and then incubated in the starvation medium with 100 ng/ml TGF-beta1 for 24hrs. Total RNA isolation, cDNA and cRNA synthesis and genechip hybridization: Total RNA was isolated using Trizol reagent (Life Technologies, Inc., Massachusetts). cDNA and cRNA synthesis, genechip hybridization, and scanning of the Affymetrix murine expression U430 2.0 chips (the Affymetrix M430 2.0 chip contains 39,000 transcripts targeted at 34,000 well characterized genes) were performed according to the manufacturer's protocol (Affymetrix, Santa Clara, CA). Briefly, 5 mg of RNA was converted into double-stranded cDNA by reverse transcription using a cDNA synthesis kit (SuperScript Choice, Life Technologies, Inc., MA) with an oligo(dT)24 primer containing a T7 RNA polymerase promoter site added 3' of the poly(T) (Genset, La Jolla, CA). After second-strand synthesis, labeled cRNA was generated from the cDNA sample by an in vitro transcription reaction supplemented with biotin-11-CTP and biotin-16-UTP (Enzo, Farmingdale, NY). The labeled cRNA was purified by using RNeasy spin columns (Qiagen, Valencia, CA). 15 mg of each cRNA was fragmented at 94 °C for 35 min in fragmentation buffer (40 mM Tris acetate, pH 8.1, 100 mM potassium acetate, 30 mM magnesium acetate) and then used to prepare 300 ml of hybridization mixture (100 mM MES, 0.1 mg/ml herring sperm DNA (Promega), 1M sodium chloride, 10 mM Tris, pH 7.6, 0.005% Triton X-100) containing a mixture of control cRNAs samples were heated at 94 °C for 5 min, equilibrated at 45 °C for 5 min, and clarified by centrifugation (14,000 x g) at room temperature for 5 min. Aliquots of each sample (10 mg of cRNA in 200 ml of the master mix) were hybridized to GeneChip Mouse Genome 430 2.0 Array at 45 °C for 16 h in a rotisserie oven set at 60 rpm, then washed with non stringent wash buffer (6x saline/sodium phosphate/EDTA) at 25 °C, followed by stringent wash buffer (100 mM MES (pH 6.7), 0.1 M NaCl, 0.01% Tween 20) at 50 °C, stained with streptavidin-phycoerythrin (Molecular Probe), washed again with 6x saline/sodium phosphate/EDTA, stained with biotinylated anti-streptavidin lgG, followed by a second staining with streptavidin-phycoerythrin, and a third washing with 6x saline/sodium phosphate/EDTA using the GeneChip Fluidics Station 450. The arrays were then scanned using a GeneChip Scanner 3000 (Affymetrix). Each experiment was repeated twice. Microarray Data analysis: The chips were read with Affymetrix GCOS v1.2, and the probe intensity files were modeled with DChip 1.3 (Harvard School of Public Health) in both PM-only and PM-MM modes. Consensus differentially regulated genes were initially derived from repeat experiments on the bases of a 90% CI of greater than 2-fold change in expression and with p<0.05 of error in paired t-test across repeats. This was further validated through modeling of variance between sample groups (one-way ANOVA) conducted in GeneSpring 6.0 (Silicon Genetix). The consensus gene-set was clustered in DChip and GeneSpring 6.0, with OntoExpress (Wayne State University) to explore ontological associations. Further ontological and pathway analyses were conducted with the GeneGo software and NIH's DAVID bioinformatics programs (heep://appls.niaid.nih.gov/david). Keywords = TGFBeta1 Keywords = mesangial cells Keywords = diabetic glomerulopathy Keywords: repeat sample
2006-01-01 | GSE2558 | GEO
Project description:Experiment protocol: Experiment was performed on 10 to 15 weeks old male NMRI mice (Harlan, Holland) housed in standard conditions (temperature 22°C, humidity 60 ± 10 %, artificial light from 8.00 am to 8.00 pm, normally 5 animals per cage). Animals had free access to tap water and food pellets (R36, Labfor, Stockholm, Sweden). Animals were randomly divided into healthy and diabetic groups. The diabetic group received a single peritoneal injection of streptozotocin (STZ, Sigma-Aldrich, France, 180 mg/kg) dissolved in sodium citrate buffer solution (0.1 mol/l, pH 4.5) to induce experimental diabetes similar to type 1. The other group received injection of an equal volume of buffer. Diabetes was confirmed 72 hours after the injection by urine glucose testing (Glukotest(r), Roche, Germany), and mice were characterized diabetic when urine glucose values were greater than 200 mg/dl. Diabetic and healthy animals were randomly assigned into 12 groups (n = 5 per group), which were sedentary or trained for one, three or five weeks. Training groups performed 1 hour per day of treadmill running at 21 m/min and 2.5° incline. After one day of familiarization on a rodent treadmill, the mice ran as described above 5 days per week. Mice were sacrificed 24 hours after the last training bout (respective sedentary controls at the same time) by cervical dislocation followed by decapitation. Calf muscles were removed, dissected free of fat and connective tissue, weighed, snap frozen in liquid nitrogen and stored at -80°C for further analysis. Total RNA extraction and sample preparation: Total RNA was extracted from the left calf muscle complex (soleus + gastrocnemius + plantaris) with Trizol Reagent (Invitrogen, Carlsbad, CA) and further purified with RNeasy columns (Qiagen, Valencia, CA) according to the manufacturers' protocols. Concentration and purity of RNA was determined by measuring absorbances at wavelengths 260 and 280 nm. Integrity of the RNA was checked with agarose gel electrophoresis. RNA samples were pooled within each group for microarray analyses. Concentration, purity and integrity of pooled RNA samples were checked as described above. Micro array analysis: Pooled RNA samples were analyzed with Affymetrix Gene Chip MG U74Av2 (Affymetrix , Inc., Santa Clara, CA) representing 6000 known genes and 6000 ESTs. Microarray analyses were performed according to the instructions of Affymetrix. Briefly, 5 µg of total pooled RNA was reverse transcribed using T7-(dT)24-primers and SuperScript II RT enzyme (Invitrogen). Single stranded cDNA was turned to double stranded cDNA using T4 DNA polymerase (Invitrogen). Produced cDNA was then purified and transcribed in vitro to biotin labeled cRNA using Enzo Bioarray High Yield RNA Transcript Labeling Kit (Enzo Diagnostics, Farmingdale, NY). RNA was purified and its quality was checked. Purity and quantity of RNA was measured with Nanodrop ND-1000 Spectrophotometer (Nanodrop Technologies, Montchanin, DE) and integrity was tested with agarose gel electrophoresis. Sample was then fragmented and hybridized to Affymetrix test chip to check the function of the hybridization cocktail and to ensure adequate representation of both 5´and 3´ends of the RNA. After testing, samples (15 µg) were hybridized to expression chips. After hybridization, chips were washed and stained in Affymetrix Fluidics Station 400. Arrays were stained first with R-Phycoerythrin Streptavidin (Molecular Probes, Eugene, OR), then with biotinylated anti-streptavidin antibody (Vector Laboratories, Burlingame, CA) and again with R-Phycoerythrin Streptavidin for signal enhancement. The chip was scanned with GeneArray Scanner G2500A (Agilent, Palo Alto, CA) Scaling and normalization of data: The array images were analyzed with Microarray Suite 5.0 (Affymetrix) software. All chips were scaled (global scaling) to target intensity of 50 to minimize differences between chips caused by physical differences in chips, hybridization efficiencies and manual laboratory work. The data was subjected to robust normalization that reduces the errors, which are caused by binding capacity and linearity differences between probe sets. Keywords: time-course
2004-12-10 | GSE1659 | GEO