CatalogueNumber | S7810 |
BrandFamily | Chemicon®
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TradeName | |
Description | CpGWIZ®RB1-MethylationspecificPCRassay |
Overview | MSP,performedusingtheCpGenome™DNAModificationKitandtheCpGWIZ®RB1AmplificationKit,permitssensitivedetectionofalteredDNA.BecausethisisaPCR-basedassay,itisextremelysensitive,facilitatingthedetectionoflownumbersofmethylatedallelesandthestudyofsamplescontainingsmallamountsofDNA.MSPalsoallowsexaminationofallCpGsites,notjustthosewithinsequencesrecognizedbymethylationsensitiverestrictionenzymes.Increasingthenumberofsuchsiteswhichcanbeassessedallowsrapid,finemappingofmethylationpatternsthroughoutCpGregions.Inaddition,thebisulfitemodificationisideallysuitedforanalysisofCpGislandssinceitconvertsthemajorityofcytosinestouracils,makingaregionofthegenomewhichisCG-richlessdifficulttoamplifybyPCR.
Methylation-specificPCR(MSP)employsaninitialbisulfitereactiontomodifytheDNA,followedbya"hotstart"PCRamplificationwithspecificprimersdesignedtodistinguishmethylatedDNAfromunmethylatedDNA.AsshowninFigure1,inthebisulfitereaction,allunmethylatedcytosinesareconvertedtouracilswhile5-methylcytosinesremainunaltered.Thus,thesequenceofthetreatedDNAwilldifferiftheDNAisoriginallymethylatedvs.unmethylated.PrimerscontainedintheCpGWIZ®RB1AmplificationKitaredesignedtospecificallyamplifyeachofthesequencesbaseduponthesechemically-induceddifferences.IfthesampleDNAwasoriginallyunmethylated,aproductwillbegeneratedafterPCRusingtheUprimerset.Conversely,aproductwillbegeneratedusingtheMprimersetifthesamplewasoriginallymethylated. |
BackgroundInformation | Methylationofcytosineslocated5"toguanosineisknowntohaveaprofoundeffectontheexpressionofseveraleukaryoticgenes(1).Innormalcells,methylationoccurspredominantlyinCG-poorregions,whileCG-richareas,calledCpGislands,remainunmethylated.AberrantmethylationofnormallyunmethylatedCpGislandshasbeendocumentedasarelativelyfrequenteventinimmortalizedandtransformedcells(2)andhasbeenassociatedwithtranscriptionalinactivationofdefinedtumorsuppressorgenesinhumancancers(3,4).Theretinoblastoma1(RB1)geneexhibitscharacteristichypermethylationimmanymaligninanttumors.
PreviouslydevelopedmethodstodeterminethemethylationstatusofcytosineincludedigestionwithmethylationsensitiverestrictionenzymesandgenomicDNAsequencing.Bothtechniqueshavelimitations:restrictionenzymescanonlydetectmethylationsiteswithintheirrecognitionsequenceandsequencingistimeconsuming.IncreasingthedetectionsensitivityofCpGislandmethylationhasthepotentialtodefinetumorsuppressorgenefunctionandprovidesanewstrategyforearlytumordetection.
Methylation-specificPCR(MSP)isanewtechnologyforsensitivedetectionofabnormalgenemethylationutilizingsmallamountsofDNA(5).ThisprocessemploysaninitialbisulfitereactiontomodifytheDNA,followedbyPCRamplificationwithspecificprimersdesignedtodistinguishmethylatedfromunmethylatedDNA.TheCpGenome™DNAModificationKit(S7820)containsthereagentsnecessarytoperformtheinitialbisulfitereactions,whiletheCpGWIZ®RB1AmplificationKitcontainsthereagentsrequiredforthePCRamplificationreactions. |
MaterialsRequiredbutNotDelivered | EquipmentandSupplies
a.MicrocentrifugetubesforPCRamplification
b.Aerosol-resistantPipettetips
c.Thermocycler
d.Gelelectrophoresisapparatus(verticalorhorizontal)
e.PowerSupply
f.302nmUVtransIlluminator,cameraandfilm
Reagents
a2.5mMdNTPmix(2.5mMofeachnucleotide)
b."Hotstart"Taqpolymerase
c."Hotstart"PCRreagents(seeSec.II.Protocols).
d.Reagentsforgelelectrophoresis(1XTBEand2%agarose,10%acrylamide,orsuitablehighresolutionagarose)
e.DNAMarkers(sizerange100-300bp)
f.Ethidiumbromide(10mg/mL)
g.Gel-loADIngsolution/LoadingDye
h.BisulfiteModifiedDNA(CpGenome™DNAModificationKit,S7820) |