Analysis of methylation using bisulphite sequencing相关交流-蚂蚁淘在线

Analysis of methylation using bisulphite sequencing

蚂蚁淘 /发布时间:1545759230 /浏览量:75

AnalysisofmethylationusingbisulphitesequencingContributedbyDr.A.Gratchev

Thismethodallowspreciseanalysisofmethylationinacertainregionbyconvertingallnonmethylatedcytosinesintotymines,whilemethylatedcytosinesremainunchanged.ThismethodrequiressmallamountofgenomicDNAandthereforeseemstobeveryusefulfortheanalysisofclinicalsamples,wherethematerialamountislimited.HoweverIsuggestoptimisingthemethodusinggenomicDNAfromacelllineandthenapplyittovaluablesamples.

BeforestartingtheexperimentyouhavetodevelopprimersforbisulphiteconvertedDNA.YoucangenerateamodelofbisulphitetreatedDNAbysubstitutingallcytosineswhicharenotinCGcontextintotymines.AndthendesignyourprimersinthewaythattheydonnotcontainanyCG.IfthisisimpossIBLe,youhavetouseC/TattheplaceofCinCGcontext.Usuallyprimerselectionisthemostcriticalinbisulphitebasedmethylationanalysis,sincethecomplexityofDNAisreduced.ThereforeIwouldsuggesttoselect2-3pairsofprimers,checkthemonbisulphitemodifiedDNA,andusethemostspecificones.

Protocol

IsolategenomicDNAwiththequalitysufficientforrestrictionenzymedigestion.
DigestDNA(50to200ng)withanyenzymewhichdoesnotcuttheregionofinterest,butresultinginasshortfragmentsaspossibleinsmallestpossiblevolume.Note:increasingtheamountofDNAwillmakedenaturingnotefficientenoughandthereforemakebisulphitereactionincomplete!
StopthereactionbyboilingDNAfor5min.
Add10NNaOHto0.3NfinalconcentrationanddenatureDNA37°Cfor15min.
Prepare4-5Eppendorftubeswithcoldmineraloil.
Add2xvolumeof2%lowmeltingagarosetotheDNAsolution,mixbypipettingupanddown.
Formagarosebeadsbypipetting10µlaliquotsofDNA/agarosemixtureintocoldmineraloil.Note:Don"tpipettthesecondaliquotinthetubewhereyoualreadyhaveonebead!
Transferbeadsinthetubecontaining1mlofmodifyingsolution(5Msodiumbisulphite(2.5MsodiummetABIsulphite),100mMHydroquinon).
Incubatethetubes4hat50°Cinthedark.
Washthebeads6timesfor15mininTEpH8.0.
Completethemodificationbyincubatingthebeads2timesfor15minin0.2NNaOH.
Washthebeads3timesfor15minindoubledistilledH₂O.
UseoneuloftheobtainedDNAforPCRwithselectedprimers.

ObtainedPCRproductcanbesequenceddirectly,inthiscaseyouwillobtainmoreorlessreliableresultsaboutthepercentageofmethylatedcytosineineveryposition.Anotherpossibilityistoclonetheproductandthensequence10ormoreindividualclones.Thismethodismuchmoretimeconsuming.ThirdmethodwhichcanbeusedfortheanalysisofbisulphitetreatedDNAisSingleNucleotidePrimerExtension(SNuPE).

================ 蚂蚁淘在线 ================

免责声明：本文仅代表作者个人观点，与本网无关。其创作性以及文中陈述文字和内容未经本站证实，对本文以及其中全部或者部分内容、文字的真实性、完整性、及时性本站不做任何保证或承诺，请读者仅作参考，并请自行核实相关内容

Analysis&nbsp;of&nbsp;methylation&nbsp;using&nbsp;bisulphite&nbsp;sequencing

Analysis of methylation using bisulphite sequencing