What is Genomic DNA - QIAGEN

Genomic DNA constitutes the total genetic information of an organism. The genomes of almost all organisms are DNA, the only exceptions being some viruses ... Home Knowledge&Support KnowledgeHub BenchGuide DNA WhatisGenomicDNA Introduction WhatisGenomicDNA? GenomicDNAconstitutesthetotalgeneticinformationofanorganism.ThegenomesofalmostallorganismsareDNA,theonlyexceptionsbeingsomevirusesthathaveRNAgenomes.GenomicDNAmoleculesaregenerallylarge,andinmostorganismsareorganizedintoDNA–proteincomplexescalledchromosomes.Thesize,numberofchromosomes,andnatureofgenomicDNAvariesbetweendifferentorganisms(seetableSizesandmolecularweightsofvariousgenomicDNAs).ViralDNAgenomesarerelativelysmallandcanbesingle-ordouble-stranded,linear,orcircular.Allotherorganismshavedouble-strandedDNAgenomes.Bacteriahaveasingle,circularchromosome.Ineukaryotes,mostgenomicDNAislocatedwithinthenucleus(nuclearDNA)asmultiplelinearchromosomesofdifferentsizes.EukaryoticcellsadditionallycontaingenomicDNAinthemitochondriaand,inplantsandlowereukaryotes,thechloroplasts.ThisDNAisusuallyacircularmoleculeandispresentasmultiplecopieswithintheseorganelles. SizesandmolecularweightsofvariousgenomicDNAs Organism Basepairsperhaploidgenome Molecularweightofgenome(daltons) Numberofchromosomes SV40 5243 3.4x106 - F174 5386 3.5x106 - Adenovirus2 35,937 2.3x107 - Lambda 48,502 3.2x107 - Escherichiacoli 4.7x106 3.1x109 x=1 Saccharomycescerevisiae 1.5x107 9.8x109 2x=32 Dictyosteliumdiscoideum 5.4x107 3.5x1010  x=6 Arabidopsisthaliana 7.0x107 4.6x1010 2x=10 Caenorhabditiselegans 8.0x107 5.2x1010 2x=12 Drosophilamelanogaster 1.4x108 9.1x1010 2x=8 Gallusdomesticus(chicken) 1.2x109 7.8x1011 2x=78 Musmusculus(mouse) 2.7x109 1.8x1012 2x=40 Rattusnorvegicus(rat) 3.0x109 2.0x1012 2x=42 Xenopuslaevis 3.1x109 2.0x1012 2x=36 Homosapiens 3.3x109 2.1x1012 2x=46 Zeamays 3.9x109 2.5x1012 2x=20 Nicotianatabacum 4.8x109 3.1x1012 2x=48 GenomicDNAcontainsgenes,discreteregionsthatencodeaproteinorRNA.AgenecomprisesthecodingDNAsequence,aswellastheassociatedregulatoryelementsthatcontrolgeneexpression.Nucleareukaryoticgenesalsocontainnoncodingregionscalledintrons.Thenumberofgenesvarieswidelybetweendifferentorganisms.CodingDNArepresentsonlyasmallfractionofeukaryoticgenomicDNA:thebulkoftheDNAisnoncoding,muchofwhichismadeupofrepetitivesequences.SomenoncodingDNAhasstructuralandregulatoryfunctions;however,thefunctionofmostofthisDNAislargelyunknown.Thenumberofcopiesofeachgeneticlocuspresentinacell,or‘ploidy’,alsovariesbetweenorganisms.Thesomatic(body)cellsoforganismsthatreproducesexuallyareusuallydiploid,havingtwosetsofhomologouschromosomesandhencetwocopiesofeachgeneticlocus,whilethegerm(reproductive)cellsarehaploidandhaveonlyonecopyofeachchromosome.Prokaryoticcellsarehaploid.Someplantsarepolyploid,forexample,modernwheat,whichishexaploid(sixcopiesofeachchromosome). Next DNAextractiontechnologies Previous WhatisGenomicDNA DNAextractiontechnologies WorkingwithDNA:Goodlaboratorypractice HandlingDNA Conversionsfornucleicacids:DNA SampledisruptionforextractionofgenomicDNA Disruptionmethods SpecialconsiderationsforisolatinggenomicDNAfromdifferentsamplesources StorageofDNA RestrictionendonucleasedigestionofDNA Principleofrestrictiondigestion Selectingsuitablerestrictionendonucleases Fragmentsize Methylation Blunt-ended/sticky-endedfragments Compatibilityofreactionconditions Restrictiondigestcomponents Reactionvolume Settinguparestrictiondigestion SamplestoragepriortoextractionofgenomicDNAT Blood Otherclinicalsamples Animaltissue Animal,yeast,andbacterialcellcultures Planttissue Fungalmaterial DNAcleanup IsopropanolprecipitationofDNA LigationofDNA QuantificationofDNA Spectrophotometry Fluorometry Agarosegel Spectrophotometry Fluorometry Agarosegel SpectrophotometricmeasurementofDNAconcentration AnalysisofDNAbySouthernblotting PreparationofgelsforSouthernblotting Assemblingtheblottingapparatus FixingtheDNAtotheblot DNAanalysisusinganalyticalgels Pouringanagarosegel Runninganagarosegel References X Cookieshelpusimproveyourwebsiteexperience. Byusingourwebsite,youagreetoouruseofcookies. Confirm