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Sample GSM637599 Query DataSets for GSM637599
Status Public on Dec 10, 2010
Title Male-K27Me3_1 extraction1_array1
Sample type genomic
Source name Male-K27Me3_1 extraction1_array1 channel_1
Organism Drosophila melanogaster
Characteristics strain: Y cn bw sp(genotype : y[1] oc[R3.2]; Gr22b[1] Gr22d[1] cn[1] CG33964[R4.2] bw[1] sp[1]; LysC[1] lab[R4.2] MstProx[1] GstD5[1] Rh6[1] official name : y[1]; Gr22b[1] Gr22d[1] cn[1] CG33964[R4.2] bw[1] sp[1]; LysC[1] MstProx[1] GstD5[1] Rh6[1] )
developmental stage: Adult Male
genotype: y[1] oc[R3.2]; Gr22b[1] Gr22d[1] cn[1] CG33964[R4.2] bw[1] sp[1]; LysC[1] lab[R4.2] MstProx[1] GstD5[1] Rh6[1]
Sex: Male
Extracted molecule genomic DNA
Extraction protocol Collection of Drosophila adult males 2-3 days old for further ChIP experiments or RNA extraction.
Formaldehyde Cross-linking of Chromatin from any Drosophila tissue (Embryos, Larvae, Pupae, Adult flies).1. Homogenize the material (about 150-200 mg of embryos, pupae, adµlts, larvae, sufficient for four-five independent immuno-precipitations) in 5 ml of buffer A1 + 1.8% formaldehyde (290 µl of 37% solution) at room temperature using first a Potter homogenizer and then a Douncer with type A pestle (3 strokes). Wait 15? (total time starting from beginning of homogenization). Add glycin solution to 225 mM (540 µl of 2.5 M solution for 6 ml of cross-linked mixture), mix and incubate 5?. Put on ice. Keep on ice unless specified.2. Transfer the homogenate to a 15 ml tube. Centrifuge 5 min, at 4000 g at 4°C. Discard supernatant. Add 3 ml of buffer A1, resuspend pellet and spin down the same way. Repeat washing step 3 times.3. Wash once in 3 ml of lysis buffer without SDS. Spin down, 5 min at 4000g.4. Resuspend cross-linked material in 0.5 ml of lysis buffer and add SDS to 0.1% (2.5 µl) and N-lauroylsarcosine to 0.5% (12.5 µl). Incubate 10 min at 4°C in a rotating wheel.5. Sonicate in Polypropylene 15ml Falcon tubes according to .Diagenode instructions. The settings are: High power, 15 minutes, 30 seconds off, 30 seconds on. The water bath shoµld be kept cold either in a cold room or by a cold water pump.6. Rotate 10'. Transfer to eppendorf tubes and centrifuge 5', room temperature at maximum speed. Transfer supernatant to the new tube. Add another 0.5 ml of lysis buffer to the pellet, rotate for 10 min. Repeat centrifugation and combine supernatants. Centrifuge the combined supernatant 2x10 min at max speed. The supernatant from this stage will be referred as chromatin extract. Chromatin can be stored at ?80°C for several months at this stage. Add sodium azide to 0.02% for storage.7. [Optional : Purification of chromatin. Put chromatin extract in Centricon YM-100 column (4212), centrifuge 3x40' (or more) at 1000 g while adding lysis buffer. At least 3 vol. of lysis buffer should pass through column. Bring the final volume of chromatin extract to 1 ml by lysis buffer + protease inhibitors.][edit]
Solutions and MaterialsLysis buffer: (see above)5mg/ml RNaseA (DNase free)PAS suspension: 100 mg of CL-4B (Amersham, 17-0780-01) PAS shoµld be resuspended in 1 ml of lysis buffer + protease inhibitors + 0.1 mg/ml BSA for 50 %v suspension. Wash in lysis buffer 2-3 times, overall equilibration time 1h. Store up to one week at 4 C.TE: 10 mM Tris-HCl pH 8.0, 1 mM EDTAElution buffer1: 10 mM EDTA, 1% SDS, 50 mM Tris-Cl pH 8.Elution buffer2: TE+0.67% SDS.LiCL 4M? Protocol 1. To an amount of chromatin corresponding to 150 mg of biological material, suspended in a final volume of chromatin extract of 1 ml (in lysis buffer + protease inhibitors), add 100 µl of PAS suspension for preincubation. Incubate several hours or overnight at 4°C, then remove PAS. Crosslinked chromatin at this stage can be stored several days at 4°C or frozen at ?70°C.2. [Optional : Check for amount of DNA. From the 1 ml solution above, take a 100 µl aliquot, Add proteinase K up to 100 ug/ml and SDS to 1%, incubate 6h at 60°C, then 20 min at 70°C, add RNAse to 50 ug/ml and incubate additional 2h at 37°C. Phenol-chlorophorm extract, ethanol precipitate. Run on an agarose gel to check amount and size of DNA.]3. Separate chromatin sample into 4x250 µl aliquots (one aliquot is enough for one IP but the amount may be decreased further). Immunoprecipitate chromatin by adding the antibody (Ab) of interest (amount of Ab shoµld be determined empirically, usually the same concentration than for a successfµl IF experiement). Keep a control sample without Ab IP, named "Mock".4. Incubate 4 h at 4°C on a head to head rotating wheel, then add 50 µl of PAS suspension and incubate 4 h or overnight. Spin down PAS and proceed to washes.5. Wash PAS 4x with lysis buffer, followed by 2x with TE (without protease inhibitors). Each wash is for 5 min at 4°C, using 1 ml of solution.6. Elution of precipitated material. Spin down PAS. Add 100 µl of elution buffer, mix and incubate 10 min at 65°C. Spin down PAS and transfer supernatant to new tube. Add 150 µl of elution buffer 2 to PAS, mix, centrifuge at fµll speed and transfer eluate to a tube together with the eluate from the first centrifugation. The combined material is the "chromatin precipitate" (approx. 250 µl).7. Incubate precipitate 6 h (or overnight) at 65 C to reverse cross-links. Add 250 µl of Proteinase K solution, incubate at 50°C 2-3 h.8. Add 55 µl of 4M LiCl and 500 µl of phenol-chlorophorm. Mix and microfuge at fµll speed at RT. Transfer aqueous phase to a new tube and precipitate with 1 ml of 100% ethanol. Wash with 750 µl of 70% ethanol. Spin down and dry precipitate.9. Dissolve in 25 µl of water. This is the chromatin immunoprecipitate or ?Native ChIP? sample.
LM-PCR amplification of the native ChIP sample to obtain a sufficient quantity for further hybridization on microarrays.
Label cy3
Label protocol Attached as supplementary file
Hybridization protocol This protocol is used for hybridization of ChIP samples on 244K Agilent arrays. The hybridization solution is composed of 5 ug each of Cy3- and Cy5-labeled DNA, 50 ug of salmon sperm DNA, Agilent Blocking Agent and Agilent Hyb Buffer. The mixture is heated to 95*C for 3 min and then 37*C for 30 minutes immediately prior to hybridization. Samples are hybridized for 40 hours at 65*C. After hybridization the slides are washed in Agilent Wash Buffer 1 for 5 minutes at room temperature and then in Agilent Wash Buffer 2 for 5 minutes at 31*C.
Scan protocol Arrays are scanned on Agilent's DNA Microarray Scanner G2505B at a resolution of 5 microns. Data is extracted from the images using Agilent's Feature Extraction Software
Description channel ch1 is ChIP DNA; Antibody information listed below: official name: H3K27me3;target name: H3K27me3;host: Rabbit;antigen: KLH-conjugated synthetic 2X-branched peptide containing the sequence ?AR(me3K)SAP? in which me3K corresponds to trimethyl-lysine at residue 27 of human histone H3.;clonal: Polyclonal;purified: Affinity;company: Upstate-Millipore;catalog: 07-449;
Data processing Agilent ChIP data processing:KW:1 protocol. We utilized Agilent 244 K array sets for carrying out ChIP-chip experiments. The Drosophila melanogaster genome is tiled using 3 array sets with mean probe resolution of ~160 base pairs. We preprocessed microarray data to normalize it and reduce experimental noise as described in Qi et al. (Qi et al., Nature biotechnology 2006). In short, the raw intensities from each channel was divided by the median intensity from that channel before computing a ratio to arrive at a median adjusted ratio. We further subtracted average value of negative control probes on the array and then added one as a regularization parameter. For factors that mark regions (e.g. H3K27me3), the data was quantile normalized, replicates were merged and HMM based segmentation was carried out.
Submission date Dec 09, 2010
Last update date Dec 10, 2010
Contact name DCC modENCODE
Phone 416-673-8579
Organization name Ontario Institute for Cancer Research
Street address MaRS Centre, South Tower, 101 College Street, Suite 800
City Toronto
State/province Ontario
ZIP/Postal code M5G 0A3
Country Canada
Platform ID GPL6951
Series (1)
GSE25946 AdultMale-H3K27me3

Supplementary file Size Download File type/resource
GSM637599_Male-K27Me3-1-251918410206.txt.gz 23.3 Mb (ftp)(http) TXT
Processed data are available on Series record

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