Gene expression in vitamin K2-induced HepG2 cells
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Motoyuki Otsuka
PROVIDER: E-GEOD-25762 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:Human hepatocellular carcinoma cells, HepG2 , cultured in DMEM containing 10% fetal calf serum. To study gene expression changes induced by Vitamin K2, total RNA was isolated following the Isogen procedure (Nippon-gene, Tokyo, Japan) from HepG2 cells with and without 50 microM of Vitamin K2 treatment for three days. The cDNA microarrays Human Oligo Chip 30K “AceGene” subset A was purchased from Hitachi Software Engineering Co. (Yokohama-City, Japan). This array contains 10368 kinds of gene-specific 50 mer sense oligonucleotides. Subset A contains mainly known function ORF oligo probes. Preparation of fluorescent cDNA targets by an indirect labeling approach was performed using PowerScript reverse transcription kit (Clontech). First-strand cDNAs were synthesized from 30 microg of total RNA from HepG2 cells treated with or without Vitamin K2 using random primer and PoweScript Fluorescent Labelling Kit. Monofunctional, N-hydroxysuccinimide-activated fluorescent dyes (Cy3 and Cy5; Amersham) were coupled to the cDNAs by reaction with the amino functional groups. Untreated cells were labeled with Cy3 as a control and treated cells with Cy5 as a sample. After free dyes were removed using MinElute Purification kit (Qiagen), the targets were mixed together and added to the microarrays, and then incubated overnight (16 hours) at 42?C. The slides were washed at 30?C in each with 2x SSC, 0.1% SDS and 2x SSC for 10 min and 5 min, respectively, and washed in 1x SSC for 5 min. Fluorescent images of the hybridized microarrays were scanned with a fluorescence laser confocal slide scanner (Affymetrix 428 Array Scanner, Affymetrix, Santa Clara, CA). The Cy3 and Cy5 intensities with background subtraction were determined by ImaGene 4.2 software (BioDiscovery, Marina Del Rey, CA). The expression data were then filtered based on their channel intensities, spot size and flag (missing or inaccurate data), and the Cy5/Cy3 ratios were calculated and normalized by median-centering the log-ratio of all genes.
2010-12-01 | GSE25762 | GEO
Project description:MicroPoly(A)Pure kits (Ambion) were used to prepare mRNA from P. salmonis-infected and control Atlantic salmon head kidney. Head kidney mRNA samples were prepared from pooled (n = 10) infected or control kidney. Approximately 200 ng of infected or control head kidney mRNA was used as template in aRNA synthesis reactions. Two infected head kidney samples were pooled to yield 8.9 ug of aRNA, and a single control head kidney sample contained 8.4 ug of aRNA. Infected and control head kidney aRNA samples were visualized on agarose gels to check quality and quantity (data not shown). Except for the amounts of aRNA and reverse transcription (RT) primer used, head kidney target labeling reactions and microarray hybridizations were identical. Head kidney target syntheses used 2 ug of aRNA and 2 ug of random primers (Roche). RT primers were mixed with aRNA samples, and nuclease-free H2O (Invitrogen) was added to make 10 ul total volume. Samples were incubated at 70 degrees C for 4 min, then placed on ice. RT reactions included 50 mM Tris HCl pH 8.3, 75 mM KCl, 3 mM MgCl2, 10 mM DTT, 0.5 mM each dATP, dCTP, and dGTP, 0.2 mM dTTP, 0.05 mM Cy3-dUTP or Cy5-dUTP (Amersham), 40U RNAguard ribonuclease inhibitor (Amersham), and 400U Superscript II Rnase H- reverse transcriptase (Invitrogen). RT reactions were incubated at 42 degrees C for 2.5 h, followed by addition of 0.025U RNase A (Sigma) and 1.5U RNase H (New England BioLabs) and incubation at 37 degrees C for 30 min. Labeled targets were cleaned using the Qiaquick PCR purification kit (Qiagen) and precipitated, with 300 mM sodium acetate, 1 ul of 20 ug/ul glycogen (Invitrogen), and 2.5 volumes of 100% ethanol, at -20 degrees C overnight. Each labeled target was recovered by centrifugation (14,000 rpm, 4 degrees C, 1 h), washed in 70% ethanol, air-dried, and resuspended in 60 ul of hybridization buffer: 50% deionized formamide, 5X SSC, 0.1% SDS, 5 ul of 5 ug/ul oligo dT (5’T18[Q-N]3’), 5 ul of 2 ug/ul BSA (Pierce), and 2 ul of 10 ug/ul sonicated human placental DNA (Sigma). Targets were incubated at 96 degrees C for 3 min, and then at 65 degrees C until applied to microarrays. Microarrays were prepared for hybridization by washing 2 X 5 min in 0.1% SDS, washing 5 X 1 min in MilliQ H2O, immersing 3 min in 95 degrees C MilliQ H2O, and drying by centrifugation (2000 rpm, 5 min, in 50 ml conical tube). Microarray hybridizations were run in the dark under HybriSlips hybridization covers (Grace Biolabs) in slide hybridization chambers (Corning) submerged in a 45 degrees C water bath for 16 h. Coverslips were floated off in 45 degrees C (1X SSC, 0.2% SDS), and arrays were washed 1 X 10 min in 45 degrees C (1X SSC, 0.2% SDS), 3 X 4 min in room temperature (0.1X SSC, 0.1% SDS), and 4 X 4 min in room temperature 0.1X SSC. Slides were dried by centrifugation as before. Fluorescent images of hybridized arrays were acquired immediately at 10 um resolution using ScanArray Express (PerkinElmer). The Cy3 and Cy5 cyanine fluors were excited at 543 nm and 633 nm respectively, and the same laser power (90%) and photomultiplier tube (PMT) settings were used for all slides in a study (PMT 75 Cy3, PMT 63 or 64 Cy5 for head kidney study). Fluorescent intensity data were extracted from TIF images using Imagene 5.5 software (Biodiscovery). Keywords: other
2004-02-11 | GSE1031 | GEO
Project description:MicroPoly(A)Pure kits (Ambion) were used to prepare mRNA from P. salmonis-infected and control Atlantic salmon macrophages. Infected and control (24 h incubation) macrophage mRNA samples were subjected to two rounds of amplification using the MessageAmp aRNA kit (Ambion) and manufacturer's instructions. Approximately 400 ng of macrophage mRNA was used as template in the first round of amplification, yielding 8.1 ug of infected macrophage aRNA and 7.8 ug of control macrophage aRNA. Approximately 1 ug of first-round macrophage aRNA was used as template in the second round of amplification, yielding 81.2 ug of infected macrophage aRNA and 83.3 ug of control macrophage aRNA. Infected and control macrophage aRNA samples were visualized on agarose gels to check quality and quantity. Except for the amounts of aRNA and reverse transcription (RT) primer used, macrophage target labeling reactions and microarray hybridizations were identical. Macrophage target syntheses used 5 ug of second-round aRNA and 5 ug of random primers (Roche). RT primers were mixed with aRNA samples, and nuclease-free H2O (Invitrogen) was added to make 10 ul total volume. Samples were incubated at 70 degrees C 4 min, then placed on ice. RT reactions included 50 mM Tris HCl pH 8.3, 75 mM KCl, 3 mM MgCl2, 10 mM DTT, 0.5 mM each dATP, dCTP, and dGTP, 0.2 mM dTTP, 0.05 mM Cy3-dUTP or Cy5-dUTP (Amersham), 40U RNAguard ribonuclease inhibitor (Amersham), and 400U Superscript II Rnase H- reverse transcriptase (Invitrogen). RT reactions were incubated at 42 degrees C for 2.5 h, followed by addition of 0.025U RNase A (Sigma) and 1.5U RNase H (New England BioLabs) and incubation at 37 degrees C for 30 min. Labeled targets were cleaned using the Qiaquick PCR purification kit (Qiagen) and precipitated, with 300 mM sodium acetate, 1 ul of 20 ug/ul glycogen (Invitrogen), and 2.5 volumes of 100% ethanol, at -20 degrees C overnight. Each labeled target was recovered by centrifugation (14,000 rpm, 4 degrees C, 1 h), washed in 70% ethanol, air-dried, and resuspended in 60 ul of hybridization buffer: 50% deionized formamide, 5X SSC, 0.1% SDS, 5 ul of 5 ug/ul oligo dT (5'T18[Q-N]3'), 5 ul of 2 ug/ul BSA (Pierce), and 2 ul of 10 ug/ul sonicated human placental DNA (Sigma). Targets were incubated at 96 degrees C for 3 min, and then at 65 degrees C until applied to microarrays. Microarrays were prepared for hybridization by washing 2 X 5 min in 0.1% SDS, washing 5 X 1 min in MilliQ H2O, immersing 3 min in 95 degrees C MilliQ H2O, and drying by centrifugation (2000 rpm, 5 min, in 50 ml conical tube). Microarray hybridizations were run in the dark under HybriSlips hybridization covers (Grace Biolabs) in slide hybridization chambers (Corning) submerged in a 45 degrees C water bath for 16 h. Coverslips were floated off in 45 degrees C (1X SSC, 0.2% SDS), and arrays were washed 1 X 10 min in 45 degrees C (1X SSC, 0.2% SDS), 3 X 4 min in room temperature (0.1X SSC, 0.1% SDS), and 4 X 4 min in room temperature 0.1X SSC. Slides were dried by centrifugation as before. Fluorescent images of hybridized arrays were acquired immediately at 10 um resolution using ScanArray Express (PerkinElmer). The Cy3 and Cy5 cyanine fluors were excited at 543 nm and 633 nm respectively, and the same laser power (90%) and photomultiplier tube (PMT) settings were used for all slides in a study (PMT 72 Cy3, PMT 63 or 64 Cy5 for macrophage study). Fluorescent intensity data were extracted from TIF images using Imagene 5.5 software (Biodiscovery). Keywords: other
2004-02-11 | GSE1012 | GEO
Project description:We used complementary DNA microarray to analyze the gene expression profiles in different proglottids of Moniezia expansa. A total of 4056 sequences including full length and partial complementary DNAs representing novel, known, and control genes were analyzed. We utilized cDNA array for detection of gene expression profiles of different proglottids of M.expansa. The present study provides some interesting data to better understanding the mechanisms of procreation and may suggest some potential target molecules for a more effective treatment on verminosis. 1.Construction of microarray By clustering the 2,642 sequences from the cDNA library, 1,078 unigenes of M.expansa, including full-length and partial cDNAs representing novel or known genes, were obtained for array construction. The negative control spots of non-tapeworm origin in the chip were the rice genes (48 spots). In addition, the array included 9 known genes(54 spots) as positive control genes that were provided by our library and 24 empty spots. Unigenes and all control genes were cloned into plasmid vector. The DZH (TC) chips were constructed by United Gene Holdings Limited of China (Shanghai, China) according to the method described by Li et al. The cDNA inserts were amplified by use of the polymerase chain reaction (PCR) using universal primers to plasmid vector sequences and were then purified. All PCR products were examined by agarose gel electrophoresis to ensure the quality and the identity of the amplified clones as expected. Then the amplified PCR products were dissolved in a buffer containing 3×SSC solution. The solution with amplified PCR products were spotted onto glass slides (model DZH-TC) using a Cartesian PixSys 7500 motion control robot (Cartesian Technologies, Irvine, CA., USA) fitted with ChipMaker Micro-Spotting Technology (TeleChem International, Sunnyvale, CA., USA). The glass slides were then hydrated for 2 h in 70% humidity, dried for 0.5 h at room temperature, and UV crosslinked (65 mj/cm). They were further processed at room temperature by soaking in 0.2% sodium dodecyl sulfate (SDS) for 10 min, distilled H2O for 10 min, and 0.2% sodium borohydride (NaBH4) for 10 min. The slides were dried again and ready for use. 2.RNA preparation and probe labeling Total RNAs were isolated from 6 M.expansas with scolex-neck proglottids, immature proglottids, mature proglottids and gravid proglottids. Tissue samples were ground into a fine powder in a 10 cm ceramic mortar (RNase-free) and were then homogenized in TRIzol (Biostar, Shanghai, China). After centrifugation, the supernatant was separated from the organic phase and was extracted in an equal volume of chloroform. The aqueous phase was then precipitated by an equal volume of isopropanol at 4°C, centrifuged to pellet the RNA and dissolved in Milli-Q H2O. The fluorescent cDNA probes were prepared through reverse transcription with Cy3- or Cy5-deoxy UTP (Amersham Pharmacia Biotech, Piscataway, NJ, USA) as follows: 5 μg of oligo(dT18) was added and annealed to 3μg of mRNA by heating the mixture to 70˚C for 10 min, and then chilling it on ice. The final reaction buffer mixture contained dNTPs (200 μM dATP, dCTP and dGTP; 60 μM dTTP; and 60 μM Cy3- or Cy5-dUTP), 2 μl of Superscript II reverse transcriptase (Invitrogen, Carlsbad, CA, USA) and 1×reaction buffer 10μl. The reactions were carried out at 42 ºC for 2 h. RNA was hydrolyzed by adding 4 μl of 2.5 M NaOH, incubating the mixture at 65 ºC for 10 min and then neutralizing it with 4 μl of 2.5 M HCl. The RNA samples from the scolex-neck proglottids were labeled with Cy3-dUTP and those from immature proglottids, mature proglottids and gravid proglottids, respectively, were labeled with Cy5-dUTP. The two color probes were then mixed and diluted to 500 μl with TE, and concentrated using a Microcon YM-30 filter (Millipore, Bedford, MA, USA) to 10 μl. The sample was then vacuum dried. 3.Hybridization The probe was dissolved in 20 ml of hybridization solution (5×SSC (0.75M NaCl and 0.075M sodium citrate), 0.4% SDS, 50% formamide). Microarrays were pre-hybridized with a hybridization solution containing 0.5 mg/ml of denatured salmon sperm DNA at 42°C for 6 h. Fluorescent probe mixtures were denatured at 95°C for 5 min and then applied onto the pre-hybridized chip under a cover glass. Chips were hybridized at 42°C for 15-17 h. Next, the hybridized chips were each washed at 60°C for 10 min in solutions of 2×SSC and 0.2% SDS, 0.1×SSC and 0.2% SDS, 0.1×SSC and then dried at room temperature. 4.Detection and analysis The chips were scanned with a ScanArray 4000 (GSI Lumonics, Bellerica, MA, USA) at two wavelengths, 635 and 532 nm, to detect emission from both Cy5 and Cy3, respectively. The acquired images were analyzed using GenePix Pro 3.0 software. The intensities of each spot at the two wavelengths represent the quantity of Cy3-dUTP and Cy5-dUTP. Ratios of Cy5 to Cy3 were computed using the GenePix Pro 3.0 median of ratio method. Overall intensities were normalized using the corresponding GenePix default normalization factor. All spots flagged “Bad” or “Not Found” by GenePix software were removed from the final data. Only genes with raw intensity values for both Cy3 and Cy5 of >200 were chosen for differential analysis. Genes were identified as differentially expressed if the ratio was >2 or <0.5, or the absolute value of base 2 logarithm of the ratio was >1 or < -1.
2009-12-01 | GSE13892 | GEO
Project description:P. aeruginosa PAO wildtype Cy3 PA3898 mutant Cy5
| PRJNA491282 | ENA
Project description:The objective of the present study was to use our own fabricated bovine liver cDNA microarray to profile genome-wide expression patterns of genes in the liver of cow throughout pregnancy. Ten-microgram of pooled liver total RNA obtained from nonpregnant cycling cows was reverse transcribed in the presence of cyanine-3-fluorescent dye (Cy3)-conjugated dUTP (Amersham Pharmacia Biotech) by using Superscript II reverse transcriptase (Life Technologies, Rockville, MD) to yield Cy3 fluorescence-labeled control cDNA probe. Similarly, liver total RNA obtained from cows on days 19, 27, 49, 58, 150 and 245 of pregnancy was separately reverse transcribed in the presence of Cy5-conjugated dUTP by using Superscript II reverse transcriptase to yield Cy5 fluorescence-labeled test cDNA probe. After a 2-h reverse transcription reaction at 42oC, RNA was degraded by addition of 1.5 µl of an alkaline solution (1N NaOH / 20 mM EDTA), and neutralized by addition of 1.5 µl 1N HCl. The labeled control cDNA probe and test cDNA probe were then mixed and washed by centrifugation with TE (Tris-EDTA, pH 7.0) first and then with TE, 20 µg Salmon sperm DNA, 20 µg polyA and 20 µg yeast RNA in a Microcon YM-30 column (Millipore, Bedford, MA). The concentrated probe mix was adjusted with TE to a volume of 24.8 µl, denatured at 100oC for 2 min, spun for a few min and made to a final hybridization volume of 31 µl with 5.27 µl 20XSSC and 0.93 µl 10% SDS and kept at room temperature until used. Before hybridization, microarray glass slides were immersed in 0.2% SDS for 2 min followed by two washes each 2 min in autoclaved Milli Q water, and subjected to blocking in 180 ml of Methyl Pyrrolidinone (Aldrich) containing 2.7 g Succinic Anhydride (WAKO, Japan) and 15.3 ml 1M Boric acid (pH 8.0) solution for 20 min. Slides were then washed with autoclaved Milli Q water, and the spotted cDNA targets (microarray) were denatured in boiling water for 2 min. The slides were dehydrated in 100% ethanol for 2 min and air dried by spinning at a low speed. The mixture of labeled probes, for example, the control (Cy3) and test (Cy5), were then applied to the microarray, placed a cover slip carefully and incubated at 65oC for 14 – 16 h in a custom slide chamber with humidity maintained by a small reservoir of 3 x SSC. In addition, 3 - 6 µl of 3 x SSC was spotted at each corner of the slide, as far away from the array as possible. After incubation for 14 – 16 h at 65oC, the slides were washed in 2 x SSC / 0.03% SDS for 2 min, followed by washing in 2 x SSC, 1 x SSC and 0.2 x SSC, each for 2 min with gentle agitation, and air dried by spinning at a low speed. All hybridizations were performed in duplicate except those of days 19 and 27, where no reverse labeling was done. In addition, day 245 of pregnancy had three samples hybridized with two of them being labeled using the same dye combination and the other is reverse labeled. In the reverse labeling procedure, for example, the control liver cDNA and test liver cDNA, which had been first labeled with fluorescent dyes Cy3 and Cy5, respectively, were then labeled with Cy5 and Cy3, respectively. The microarray hybridization images were immediately scanned by GenePix 4000B (Axon Instrument, Union City, CA). The images acquired by scan were analyzed by GenePix Pro 4.0 software. The absolute feature (microarray spot) and background intensity of Cy3 and Cy5 for each feature on the array was obtained for the hybridized images. The local background intensity of each spot was smoothed by the local weight regression smoother (lowess smoother) and subtracted from feature intensity data. The subtracted intensity data were subjected to non-parametric regression and local variance normalization. The non-parametric regression can reduce intensity-depended biases. Compared with the linear regression, the accuracy is improved, if the points in scatter plot of Cy3 vs. Cy5 were not distributed around the straight line. The local variance normalization controls the noise (background) in the raw data to a greater extent where the normalized data, in many cases, did not show significant fold-differences in comparison with background-subtracted raw intensity ratios, which frequently displayed higher fold-differences. Thus, the variance method that we employed to bovine liver array data has produced much reliable normalized ratios. To group liver genes with similar expression patterns throughout bovine pregnancy, two clustering algorithm were employed. The hierarchical clustering algorithm was performed using the software, Cluster 3.0, created and made freely available by Dr. Michiel de Hoon (http://bonsai.ims.u-tokyo.ac.jp/~mdehoon/software/cluster/software.htm) based on the original version written by Dr. Michael Eisen (http://rana.lbl.gov/), and the software TreeView (http://rana.lbl.gov/). For hierarchical clustering, genes with either 2 or more than 2-fold induction or 2 or more than 2-fold repression at least at one point of the sampling period were selected. All ratio values were log transformed (base 2) to treat inductions or repressions of identical magnitude as numerically equal but with opposite sign, and subjected to centroid linkage clustering. Self-Organizing Maps (SOMs) algorithm was performed using the software GeneCluster 2 made freely available by Whitehead Institute Center for Genome Research (http://www-genome.wi.mit.edu/cancer/software/genecluster2/gc2.html). The SOMs were performed on the present data to better visualization of clusters of genes with their expression patterns plotted on an x-y axis. For SOMs, genes with either 1.5-fold (and above) induction or 1.5-fold (and above) repression at least at one point of the sampling period were selected. The minimum fold difference i.e., 1.5-fold, chosen for the analyses in the present study was based on the calculation that the technical variation contributing to the expression level of each individual gene due either to different labeling efficiencies of cyanine dyes or labeling procedure or both, was found to be within the range of 1.41-fold induction or repression. Therefore, either the induction or the repression of a particular gene by 1.5-fold or above was considered significant. Keywords = differential liver gene expression Keywords = bovine pregnancy Keywords = hierarchical clustering Keywords = self-organizing maps Keywords: time-course
2003-11-14 | GSE458 | GEO
Project description:This series repressents the data set from the paper "Expression microarray analysis and oligo array CGH of aquired gemcitabine resistance in mouse colon reveals selection for chromosomal aberrations". Biological material: One solid mouse tumor "Colon 26A" was routinely maintained by successive transplantation. A subset of mice with this tumor was treated at the maximum tolerable dosage of Gemcitabine and successively transplanted 5 times and similarly treated. The last passage was completly resistant and designated, "Colon 26G". Expression array: Total RNA was isolated from frozen mouse tumors using Tryzol. Single stranded cDNA was synthetized from 30 mg of total RNA by reverse transcription using aminoallyl labeled dUTP (Ambion). Labelling was performed according to the aminoallyl labeling protocol. Briefly, cDNA was incubated at room temperature for 1 h with fluorolink monofunctional cy5 or cy3 (Amersham) followed by 15 min 4 M hydroxylamine treatment. Uncoupled dyes were removed using Qiaquick PCR purification columns (Qiagen) and mixed with 12 mg poly(dA) (Amersham), 60 mg yeast tRNA (Sigma) and 24 mg Cot-1 DNA (Invitroen). The probe was dissolved in 127 ml hybridization mixture containing 46% formamide, 9.5% dextran sulfate, 2x SSC and 0.2% SDS. The probe was heated to 70°C for 10 min and annealed at 37°C for 1 h. Slides were hybridized for 14 h at 37°C over-night (HyArray 12™, Perkin Elmer). After hybridization the slides were washed in the HybArray 12™ with 50% formamide, 2x SSC, pH 7 at 35°C for 15 min, followed b PI buffer (0.1 M sodium phosphate, 0.1% Igepal Ca630, pH 8) at room temperature and 3 washes of 0.2x SSC, 0.1x SSC and 0.01x SSC at room temperature followed by centrifugation. Arrays were scanned using a laser scanner (ScanArray Express, Perkin Elmer) and analysed using ImaGene version 5.6. Cy5 cy3 ratios are calculating by taking the log2 of the signal mean of each spot minus the median background mean of all spots on the array. This is followed by a standard normalization for spot intensity and calculation of the ratios. Keywords: other
2005-12-21 | GSE2352 | GEO
Project description:Samples and RNA preparation: The series is composed of 4 hybridizations for analysis of differentially expressed genes in the liver of ciprofibrate dosed vs. control rats. Rats (200-250 g) were given (by gastric intubation) tap water (control group, n=5) or ciprofibrate (50 mg/kg body weight, once daily for 60 days, n=4). Liver total RNA extraction was performed first by ultracentrifugation on a cesium chloride cushion and then using TRIZOL Reagent (GIBCO BRL Life Technologies, New York, NY). Labeling and hybridization: One microgram of total RNA from the control pool (n=5), and from each ciprofibrate dosed rat was reverse transcribed and labeled with Cy3- and Cy5-attached dendrimer, respectively, using 3DNA Array Detection Submicro kit as described in the manufacturer's protocols (Genisphere, Montvale, NJ). The labeling reactions were also spiked with exogenous control RNAs (Stratagene) at expected Cy5/Cy3 ratios of 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 0.5, 0.33, 0.25 and 0.125 for control spike 1, 2, 3, 4, 5, 6, 8, 9, 10 and 7, respectively. The Cy3 and Cy5 labeled samples (combined volume 5 microliter) were mixed with 30 microliter of the hybridization solution containing 0.25 M NaPO4, 1 mM EDTA, 4.5% SDS, 1 x SSC, 2 x Denhardt's solution, 0.25 microliter antifade reagent (Genisphere) and 0.2 microgram mouse COT-1 DNA (GIBCO BRL Life Technologies), added onto the array and covered with 22 x 50mm cover slip. The array was assembled into humidified hybridization chamber (Corning) and hybridized at 65oC for 18 h by submerging in a water bath. Post-hybridization washes were done once in 2 x SSC, 0.2% SDS at 55oC for 15 min, then in 2 x SSC at room temperature for 15 min, and finally with 0.2 x SSC at room temperature for 15 min. Scanning, image analysis and data processing: Arrays were scanned at 10 micrometer resolution with a confocal laser scanner constructed in-house in collaboration with NEMKO (Trondheim, Norway) according to a prototype developed at NHGRI (http://www.nhgri.gov/DIR/LCG/15K(HTML/). Microarray image analysis was done with MicroArray Suite software version 2.1 with globally normalization (Scanalytics, Inc., Fairfax VA). First, spots undetected (target intensity=1) in at least one array were excluded. Then, spots with signal intensity (averages of the 4 arrays) less than 300 in both channels were removed. The fluorescence intensity ratios (Cy5/Cy3) for genes measured from probes spotted in duplicate were averaged for each slide. Then, mean ratios of the 4 hybridizations were calculated for each gene, and differentially regulated genes were determined using 1.4 fold change cutoff values (1.4 for up-regulated or 0.7 for down-regulated genes). Keywords: other
2003-03-31 | GSE335 | GEO
Project description:Gene expression in vitamin K2-induced HepG2 cells
| PRJNA134059 | ENA
Project description:The gene expression profiles of the differentiating xylem of 91 Eucalyptus grandis backcross individuals were characterized following a loop design (Churchill, G.A. Nat Genet. 2002 Dec;32 Suppl:490-5). In this design, RNA from genotype 1666 (labeled with Cy5) was hybridized with RNA from genotype 1667 (labeled with Cy3) on the first slide(GEO accession number GSM7637); the same genotype 1667 (now labeled with Cy5) was compared with genotype 1669 (Cy3) on the second slide (GSM7638), and so on. The loop was completed when genotype 1666 (Cy3) was contrasted to individual 1796 (Cy3) on slide GSM7727. Therefore, 91 individuals (genotypes) from the E. grandis backcross population were analyzed in two replicates, one with RNA labeled with Cy3 and the other with Cy5. Keywords = Eucalyptus, xylem, microarray Keywords: ordered
2003-07-16 | GSE502 | GEO