AddNH4Ac(10Mstockorsolid)tothesampleforafinalconcentrationof2.5M,mix(spinat4C,transferthesupernatanttoanewtube;optionalspinforextrapurificationoftheDNA),add2.5volumesofEtOH,mix,andspinthistimekeepingthepellet(watchtheliquidaspouringitdownthedraintomakesurethatpelletdoesnotcomeloose).TurnthetubeupsidedownonapapertoweltoallowtheEtOHtodrainwell.Givethepelleta70%EtOHrinse(carefullyandalittleslowlyaddtheEtOHbyaDPTP:ifthepelletcomesloose,spinitagain),drainthetubeagain,anddrythepelletbriefly(underthevacuumfor5to10min)beforeresUSPendingtheDNAin10:2TE(almostalwaysTEexceptdoingadigestorligationinwhichcasetheDNAisresuspendedinH2O:lowsaltintheresuspensionbufferisimportant).OftenmultipleNH4Ac/EtOHprecipitationaredesired.IftheDNAisparticularlyimportantorifitisataverylowconcentrationi.e.<0.5µg/ml,itisbesttoincludeawaitingperiodbeforeeachspin:atleastonehour(overnightisbetter)andateitherroomtemperatureor4C.EtOHandsaltreducethesolubilityofDNA,consequently,itisbesttodraintheEtOHwell,wipingtheinsideofthetubewithaChimwipe(but,donottouchthepellet) SampleVolumeofTableMFT(0.5 ml)MFT(1.5 ml)CorexORT 250mlDNA105 ul210 ul 315 ul2.1 ml 9 ml 60.0 mlNH4Ac 35 ul 70 ul 105 ul 0.7 ml 3 ml 12.6 gEtOH350 ul700 ul1050 ul7.0 ml30 ml165.0 mlOptionalspincheck:Min/rpm15/14K20/14K10/14K25/9KMin/rpm20/14K20/14K20/14K20/14K20/14K25/9K
