protocol for epifos™ fosmid library production kit...2) e. coli f factor-based partitioning and...
TRANSCRIPT
Connect with Epicentre on our blog (epicentral.blogspot.com), Facebook (facebook.com/EpicentreBio), and Twitter (@EpicentreBio).
www.epicentre.com Lit.#149•8/2012 1 EPILIT149 Rev. A
EpiFOS™ Fosmid Library Production Kit
Cat. No. FOS0901
2 www.epicentre.com
EpiFOS™ Fosmid Library Production Kit
1. Overview of the EpiFOS Fosmid Library Production ProcessFosmid vectors1-3 provide an improved method for cloning and the stable maintenance of cosmid-sized (35-45 kb) libraries in E. coli. The stability of such large constructs in vivo is facilitated by the pEpiFOS™-5 vector that maintains the clones at single copy in the cell.
The EpiFOS Fosmid Library Production Kit will produce a complete and unbiased primary fosmid library. The kit utilizes a novel strategy of cloning randomly sheared, end-repaired DNA. Shearing the DNA leads to the generation of highly random DNA fragments in contrast to more biased libraries that result from fragmenting the DNA by partial restriction digests.
Thestepsinvolved(protocolsforsteps2-7areincludedinthismanual):
1. Purify DNA from the desired source (the kit does not supply materials for this step).
2. SheartheDNAtoapproximately40-kbfragments.
3. End-repair the sheared DNA to blunt, 5′-phosphorylated ends.
4. Size-resolve the end-repaired DNA by Low Melting Point (LMP) agarose gel electrophoresis.
5. Purify the blunt-end DNA from the LMP agarose gel.
6. Ligate the blunt-end DNA to the Cloning-Ready pEpiFOS-5 vector.
7. PackagetheligatedDNAandplateonEPI100™-T1R Plating Strain. Grow clones overnight.
pEpiFOS-5isa7518bp.fosmidcloningvectorwhichisprovidedCloning-Ready- linearized at the unique Eco72I(blunt)restrictionenzymerecognitionsite,dephosphorylated and rigorously tested for purity and recombinant cloning efficiency. Featuresofthevectorinclude:
1) Chloramphenicol-resistance as an antibiotic selectable marker.
2) E. coli F factor-based partitioning and copy number regulation system.
3) Bacteriophage lambda cos site for lambda packaging or lambda-terminase cleavage.
4) Bacteriophage P1 loxP site for Cre-recombinase cleavage.
5) BacteriophageT7RNApolymerasepromoterflankingthecloningsite.
6) Fosmid end-sequencing primers are available separately.
ApEpiFOS-5VectormapandcompleterestrictiontableisprovidedinAppendixE.
[email protected] •(800)284-8474 3
EpiFOS™ Fosmid Library Production Kit
2. Kit ContentsDesc. Concentration Quantity
Reagentsincludedinthekitaresufficienttoconstruct10fosmidlibraries.pEpiFOS™-5 Fosmid Vector: (0.5μg/μl) 20μl
(Cloning-Ready; linearized at the unique Eco72Isiteanddephosphorylated)
End-Repair 10X Buffer: 100μl(330mMTris-acetate[pH7.5],660mMpotassiumacetate,100mMmagnesiumacetate, 5 mM DTT)
dNTP Mix:(2.5mMeachofdATP,dCTP,dGTP,dTTP) 100μlEnd-Repair Enzyme Mix:(includingT4DNAPolymeraseand 50μl T4 Polynucleotide Kinase) ATP Solution (10mM) 100μlFast-Link™ DNA Ligase (40U@2U/μl) 20μlFast-Link™ 10X Ligation Buffer 100μlGELase™ Enzyme Preparation (25U@1U/μl) 25μlGELase™ 50X Buffer:(2.0MBis-Tris[pH6.0],2.0MNaCl) 200μl*Fosmid Control DNA (100ng/μl) 50μlEPI100™-T1R Phage T1-Resistant E. coli Plating strain:glycerolstock 250μl
[F–mcrA ∆(mrr-hsdRMS-mcrBC) ϕ80dlacZ∆M15 ∆lacX74recA1 endA1 araD139 ∆(ara, leu)7697galUgalKλ–rpsL nupG tonA]
MaxPlax™ Lambda Packaging Extracts 10ExtractsLigated Lambda Control DNA:(λcI857Sam7) (1μ[email protected]μg/μl) 50μlLE392MP E. coli Control strain:glycerolstock 250μl
[F–e14–(McrA–)∆(mcrC-mrr) (TetR) hsdR514 supE44 supF58lacY1 or ∆(lacIZY)6 galK2galT22metB1 trpR55λ–]
Note: MaxPlax Lambda Packaging Extracts are supplied as freeze-thaw/sonicate extracts in unlabeled single tubes. The extracts, Ligated Lambda Control DNA, and LE392MP Control Plating Strain are packaged together in a CO2-impermeable foil pouch.
Storage:StoretheEPI100-T1RPlatingStrainandtheMaxPlaxLambdaPackagingExtractsat–70°C.Exposuretohighertemperatureswillgreatlycompromisepackagingextractefficiency.OncetheMaxPlaxPackagingExtractsareopened,donoexposethemtodryice.Storetheremainderofthekitcomponentsat–20°C.Afterthawing,storetheLigatedLambdaControlDNAat4°C.
*The “T7 DNA Size Marker” and the “Fosmid Control Insert DNA” have been replaced with a single tube of “Fosmid Control DNA”. The Fosmid Control DNA is used both as a size marker and as a control insert for fosmid library production. The amount of DNA used for sizing and library production remains the same.
4 www.epicentre.com
EpiFOS™ Fosmid Library Production Kit
Additional Required Reagents
Inadditiontothecomponentsupplied,thefollowingreagentsarerequired:
LBbroth+10mMMgSO4
LBplates+12.5μg/mlchloramphenicolLow melting point (LMP) agaroseEthanol3MSodiumAcetate(pH7.0)PhageDilutionBuffer(10mMTris-HCl[pH8.3],100mMNaCl,10mMMgCl2)TEBuffer(10mMTris-HCl[pH7.5],1mMEDTA)
Quality Control
The EpiFOS Fosmid Library Production Kit is function-tested using the Fosmid Control DNAprovidedinthekit.Eachkitmustyield>107cfu/μgoftheFosmidControlDNA.TheMaxPlaxLambdaPackagingExtractshavebeentestedtogive>108pfu/μgofLigatedLambda Control DNA.
3. EpiFOS Fosmid Library Production ProtocolGeneral Considerations
1. Important! Users should avoid exposing DNA to UV light. Even exposure for short periods of time can decrease the efficiency of cloning by two orders of magnitude or more. Two methods for excising DNA from an LMP agarose gel without exposure to UV are presented in Part C.
2. The36-kbFosmidControlDNAsuppliedinthekitisusedasasizemarkerforagarose gel size-fractionation of the DNA to be cloned.
3. TheLigatedLambdaControlDNA(λcI857Sam7)andtheControlStrainLE392MPare usedtotesttheefficiencyoftheMaxPlaxLambdaPackagingExtracts(seeAppendixC).
Preparation
1. Prepare high molecular weight genomic DNA from the organism using standard methods.4ResuspendtheDNAinTEbufferataconcentrationofabout0.5μg/μl.This DNA will be the source of the clones and will be referred to as the “insert DNA” throughout this manual.
2. TheEPI100-T1R Plating Strain is supplied as a glycerol stock. Prior to beginning the FosmidLibraryProductionprocedure,streakouttheEPI100™-T1R cells on an LB plate.Donotincludeanyantibioticinthemedium.Growthecellsat37°Covernightandthensealandstoretheplateat4°C.ThedaybeforetheLambdaPackagingreaction(PartF),inoculate50mlofLBbroth+10mMMgSO4 with a single colony of EPI100™-T1Rcellsandshakeovernightat37°C.
[email protected] •(800)284-8474 5
EpiFOS™ Fosmid Library Production Kit
A. Shearing the Insert DNA
Kitcomponentusedinthisstep:Fosmid Control DNA.
ShearingtheDNAintoapproximately40-kbfragmentsleadstothehighlyrandomgeneration of DNA fragments in contrast to more biased libraries that result from partial restriction endonuclease digestion of the DNA. Frequently genomic DNA is sufficiently sheared, as a result of the purification process, that additional shearing is not necessary. TesttheextentofshearingoftheDNAbyfirstrunningasmallamountofitbyPulseFieldGelElectrophoresis(e.g.,FieldInversionGelElectrophoresis[FIGE],CHEF,etc.)withvoltageandramptimesrecommendedbythemanufacturerforseparationof10-100kbDNA.IfaPFGEapparatusisnotavailable,runthesampleona20-cmlong,1%agarosegelat30-35Vovernight.Load100ngoftheFosmidControlDNAinanadjacentgellane.Run the gel and stain with ethidium bromide.
If10%ormoreofthegenomicDNAmigrateswiththeFosmidControlDNA,thentheusercan proceed to Part B. If the genomic DNA migrates slower (higher MW) than the Fosmid Control DNA, then the DNA needs to be sheared further as described in Part A, Step 1 below. If the genomic DNA migrates faster than the Fosmid Control DNA (lower MW) then it has been sheared too much and should be reisolated.
1. Werecommendthatatleast2.5μgofDNAbeused.RandomlysheartheDNAbypassingitthrougha200-μlsmallborepipettetip.AspirateandexpeltheDNAfromthepipettetip50-100times.Examine1-2μloftheDNAona20-cmagarosegelusingtheFosmidControlDNA.If10%ormoreofthegenomicDNAmigrateswiththe Fosmid Control DNA, then the user can proceed to Part B. If the DNA is still too large,aspirateandexpeltheDNAfromthepipettetipanadditional50times.Examine1-2μlofthisDNAbyagarosegelasdescribedpreviously.
B. End-Repair of the Insert DNA
Kitcomponentsusedinthisstep:End-Repair Enzyme Mix and 10X Buffer, dNTPs and ATP.
This step generates blunt-ended, 5′-phosphorylated DNA. The end-repair reaction can be scaled up or scaled down as dictated by the amount of DNA available.
1. Thawandthoroughlymixallofthereagentslistedbelowbeforedispensing;placeonice.Combinethefollowingonice:
x μl sterilewater 8 μl End-Repair10XBuffer 8 μl 2.5mMdNTPMix 8 μl 10mMATP upto20 μgshearedinsertDNA(approximately0.5μg/μl) 4 μl End-RepairEnzymeMix 80 μl Totalreactionvolume
2. Incubateatroomtemperaturefor45minutes.
3. Addgelloadingbufferandincubateat70°Cfor10minutestoinactivatetheEnd-RepairEnzymeMix.ProceedwithSize Selection of the End-Repaired DNA in Part C.
6 www.epicentre.com
EpiFOS™ Fosmid Library Production Kit
C. Size Selection of the End-Repaired DNA
Kitcomponentsusedinthisstep:Fosmid Control DNA.
Size select the end-repaired DNA by low melting point (LMP) agarose gel electrophoresis.Ideally,usePulseFieldGelElectrophoresis(e.g.,FIGE,CHEF,etc.)withvoltageandramptimesrecommendedbythemanufacturerforseparationof10-to100-kbDNA.IfaPFGEapparatusisnotavailable,runthesampleona20cmlong,1%agarosegelat30-35Vovernight.Minigels (e.g., 10 cm) do not provide sufficient resolution of DNA in the 20- to 60-kb size range.
1. Preparea1%LMP agarose gel in 1X TAE or 1X TBE buffer.
Note: Do not include ethidium bromide in the gel solution.
2. Load100ngofFosmidControlDNAintoeachoftheoutsidelanesofthegelandload the end-repaired insert DNA in the lane(s) between the Fosmid Control DNA marker lanes.
3. Resolvethesamplesbygelelectrophoresis(forexampleatroomtemperatureovernight)ataconstantvoltageof30-35V.Visualizingandexcisingtheend-repairedDNA can be done by one of two methods described below.
Method 1
Following electrophoresis, cut off the outer lanes of the gel containing the Fosmid Control DNA. Stain the Fosmid Control DNA lanes with ethidium bromide and visualize theDNAwithUVlight.MarkthepositionoftheFosmidControlDNAinthegelusingaPasteur pipet.
Note: Do not expose the sample DNA to UV irradiation! Even short UV exposure can decrease cloning efficiencies by 100- to 1,000-fold. Reassemble the gel and excise a 2- to 4-mm wide gel slice containing sample DNA that migrated with and just slightly above (higher MW) the position of the 36-kb Fosmid Control DNA markers.
Caution: Be sure to cut the gel slice so that the DNA recovered is ≥25 kb. Cloning DNA smaller than about 25 kb may result in unwanted chimeric clones. Transfer the gel slice to a tared, sterile, 15-ml screw-cap tube.
Method 2
Following electrophoresis, stain the gel with SYBR® Gold (Molecular Probes, Inc.) according to the manufacturer’s instructions. Place the gel on a Dark Reader™ Transilluminator (Clare Chemical Research) and visualize the DNA. The Dark Reader TransilluminatorallowstheDNAtobevisualizedwithoutUVlightthuspreventingdamagetotheDNA.Excisea2-to4-mmwidegelslicecontainingsampleDNAthatmigrated with and slightly above (higher MW) the position of the 36-kb Fosmid Control DNA markers.
Caution: Be sure to cut the gel slice so that the DNA recovered is greater than or equal to 25 kb. Cloning DNA smaller than about 25 kb may result in unwanted chimeric clones. Transfer the slice to a tared, sterile, 15-ml screw-cap tube.
4. Proceed with Recovery of the Size-Fractionated DNA in Part D or store the gel sliceat4°Cto–20°Cforuptooneyear.
[email protected] •(800)284-8474 7
EpiFOS™ Fosmid Library Production Kit
D. Recovery of the Size-Fractionated DNA
Kitcomponentsusedinthisstep:GELase 50X Buffer, GELase Enzyme Preparation.
BeforebeginningthisStep,preparea70°Canda45°Cwaterbathorothertemperatureregulated apparatus.
1. Weigh the tared tubes to determine the weight of the gel slice(s). Assume 1 mg of solidifiedagarosewillyield1μlofmoltenagaroseuponmelting.
2. WarmtheGELase50XBufferto45°C.MelttheLMPagarosebyincubatingthetubeat70°Cfor10-15minutes.Quicklytransferthetubeto45°C.
3. AddtheappropriatevolumeofwarmedGELase50XBufferto1Xfinalconcentration.Carefullyadd1U(1μl)ofGELaseEnzymePreparationtothetubeforeach100μlofmeltedagarose.Keepthemeltedagarosesolutionat45°Candgentlymixthesolution.Incubatethesolutionat45°Cforatleastonehour(overnightincubationisacceptable if desired).
4. Transferthereactionto70°Cfor10minutestoinactivatetheGELaseenzyme.
5. Remove500μlaliquotsofthesolutionintosterile,1.5-mlmicrofugetube(s).
6. Chill the tube(s) in an ice bath for 5 minutes. Centrifuge the tubes in a microcentrifugeatmaximumspeed(approximately10,000rpm)for20minutesto pellet any insoluble oligosaccharides. Any “pellet” will be gelatinous, and translucent-to-opaque.Carefullyremovetheupper90%-95%ofthesupernatant,which contains the DNA, to a sterile 1.5-ml tube. Be careful to avoid the gelatinous pellet.
7. PrecipitatetheDNA.
a) Add1/10volumeof3MSodiumAcetate(pH7.0)andmixgently.
b) Add2.5volumesofethanol.Capthetubeandmixbygentleinversion.
c) Allowprecipitationfor10minutesatroomtemperature.
d) CentrifugetheprecipitatedDNAfor20minutesinamicrocentrifuge,attop speed(typically10,000-16,000rpm).
e) Carefully aspirate the supernatant from the pelleted DNA.
f ) Washthepellet2Xwithcold,70%ethanol,repeatingstepsd)ande)usingcare not to disrupt the DNA pellet.
g) Afterthesecond70%ethanolwashcarefullyinvertthetubeandallowthe pellettoair-dryfor5-10minutes(longerdrytimeswillmakeresuspensionof the DNA difficult).
h) Gently resuspend the DNA pellet in TE Buffer.
8. DeterminetheDNAconcentrationbyfluorimetry.Alternatively,estimatetheconcentration of the DNA by running an aliquot of the DNA on an agarose gel using dilutions of known amounts of the Fosmid Control DNA as standard.
Note: Measuring the DNA concentration by spectrophotometry (A260) is not recommended because the DNA concentration will not be high enough to be measured accurately.
8 www.epicentre.com
EpiFOS™ Fosmid Library Production Kit
E. Ligation Reaction
Kitcomponentsusedinthisstep:Fast-Link 10X Ligation Buffer, Fast-Link DNA Ligase, ATP, pEpiFOS-5 Cloning-Ready Vector.
1. PleaserefertoAppendixAtodeterminetheapproximatenumberoffosmidclonesthatyouwillneedforyourlibrary.Asingleligationreactionwillproduce103-106 clones depending on the quality of the insert DNA. Based on this information calculate the number of ligation reactions that you will need to perform. The ligation reaction can be scaled-up as needed.
2. Combinethefollowingreagentsintheorderlistedandmixthoroughlyaftereachaddition.
A10:1molarratioofpEpiFOS-5VectortoinsertDNAisoptimal.
0.5μgpEpiFOS-5(Cloning-Ready)Vector≈0.1pmolvector
0.25μgof≈40KbinsertDNA≈0.009pmolinsertDNA
x μl sterilewater 1 μl 10XFast-LinkLigationBuffer 1 μl 10mMATP 1 μl pEpiFOS-5Vector(0.5μg/μl) x μl concentratedinsertDNA(0.25μgof≈40kbDNA) 1 μl Fast-LinkDNALigase 10 μl Totalreactionvolume
3. Incubateatroomtemperaturefor2hours.
4. Transferthereactionto70°Cfor10minutestoinactivatetheFast-LinkDNALigase.
ProceedtoPartForstoreat–20°C.
F. Packaging the Fosmid Clones
Kitcomponentsusedinthisstep: MaxPlax Lambda Packaging Extracts, EPI100-T1R Plating Strain.
1. Thedayofthepackagingreactions,inoculate50mlofLBbroth+10mMMgSO4 with5mloftheEPI100-T1R overnight culture from the Preparation step on page 5. Shakeat37°CtoanOD600=0.8-1.0.Storethecellsat4°Cuntilneeded(PartG).Thecellsmaybestoredforupto72hoursat4°Cifnecessary.
2. Thaw,onice,1tubeoftheMaxPlaxLambdaPackagingExtractsforeveryligationreactionperformedinPartE.Forexamplethaw1tubeoftheMaxPlaxLambdaPackagingExtractsifthestandard10μlligationreactionwasdone.Thaw2tubesiftheligationreactionwasscaledupto20μl,etc.
3. When thawed, immediatelytransfer25μl(one-half )ofeachpackagingextracttoasecond1.5-mlmicrofugetubeandplaceonice.Returntheremaining25μloftheMaxPlaxPackagingExtractonto–70°CfreezerforuseinPartF,Step7.
Note: Do not expose the MaxPlax Packaging Extracts to dry ice or other CO2 source.
[email protected] •(800)284-8474 9
EpiFOS™ Fosmid Library Production Kit
4. Add10μloftheligationreactionfromPartEtoeach25μlofthethawed,extractsbeing held on ice.
5. Mixbypipettingthesolutionsseveraltimes.Avoidtheintroductionofairbubbles.Brieflycentrifugethetubestogetallliquidtothebottom.
6. Incubatethepackagingreactionsat30°Cfor90minutes.
7. Afterthe90minutepackagingreactioniscomplete,addtheremaining25μlofMaxPlaxLambdaPackagingExtractfromPartF,Step3toeachtube.
8. Incubatethereactionsforanadditional90minutesat30°C.
9. Attheendofthesecond90minuteincubation,addPhageDilutionBufferto1 ml final volumeineachtubeandmixgently.Add25μlofchloroformtoeach.Mixgentlyandstoreat4°C.Aviscousprecipitatemayformafteradditionofthechloroform. This precipitate will not interfere with library production. Determine the titer of the phage particles (packaged fosmid clones) in Part G, and then plate thefosmidlibraryinPartH.Alternatively,storethephageparticlesforuptoseveralweeksat4°C.
G. Titering the Packaged Fosmid Clones
Kitcomponentsusedinthisstep:EPI100-T1R Plating Strain from Part F, Step 1.
Before plating the library we recommend that the titer of the phage particles (packaged fosmid clones) be determined. This will aid in determining the number of plates and dilutions to make to obtain a library that meets the needs of the user.
1. Make serial dilutions of the 1 ml of packaged phage particles from Part F, Step 9 into Phage Dilution Buffer (PDB) in sterile microfuge tubes.
A) 1:102Dilute10μlofpackagedphageinto990μlofPDB. B) 1:104Dilute10μlofthe1:102dilutioninto990μlofPDB. C) 1:105Dilute100μlofthe1:104dilutioninto900μlofPDB. D) 1:106Dilute100μlofthe1:105dilutioninto900μlofPDB.
2. Add10μlofeachabovedilution,individually,to100μlofthepreparedEPI100-T1R hostcellsfromStepF1above.Incubateeachfor20minutesat37°C.
3. SpreadtheinfectedEPI100-T1RcellsonanLBplate+12.5μg/mlchloramphenicolandincubateat37°Covernighttoselectforthefosmidclones.
4. Count colonies and calculate the titer of the packaged phage particles from Part F, Step 9.
Sample Calculation:
Iftherewere200coloniesontheplatestreakedwiththe1:104 dilution, then the titer in cfu/ml,(wherecfurepresentscolonyformingunits)ofthisreactionwouldbe:
(#ofcolonies)(dilutionfactor)(1,000μl/ml) (200cfu)(104)(1,000μl/ml)___________________________________ OR _______________________ =2x108cfu/ml (volumeofphageplated[μl]) (10μl)
10 www.epicentre.com
EpiFOS™ Fosmid Library Production Kit
H. Plating and Selecting the Fosmid Library
Based on the titer of the packaged fosmid clones and the estimated number of clones required(seeAppendixA),calculatethevolumeofthepackagedfosmidclonesthatwillbe needed to prepare the fosmid library.
1. Based on the titer of the phage particles determined in Part G, dilute the phage particles from Part F, Step 9 with Phage Dilution Buffer to obtain the desired number ofclonesandclonedensityontheplate.Proceedtothenextsteporstorethedilutedphageparticlesat4°Cforuptoseveralweeks.
2. MixthedilutedphageparticlesfromPartH,Step1withEPI100-T1R cells prepared in PartF,Step1intheratioof100μlofcellsforevery10μlofdilutedphageparticles.
3. Adsorbat37°Cfor20minutes.
4. SpreadtheinfectedbacteriaonanLBplate+12.5μg/mlchloramphenicolandincubateat37°Covernighttoselectforthefosmidclones.
4. AppendixAppendix A
Determining the Approximate Number of Clones for a Complete Fosmid Library
Usingthefollowingformula5, determine the number of fosmid clones required to reasonably ensure that any given DNA sequence is contained within the library.
N = ln (1-P)/ln(1-f )
Where Pisthedesiredprobability(expressedasafraction);f is the proportion of the genome contained in a single clone; and N is the required number of fosmid clones.
Forexample,thenumberofclonesrequiredtoensurea99%probabilityofagivenDNAsequence of E. coli(genome=4.7Mb)beingcontainedwithinafosmidlibrarycomposedof40kbinsertsis:
N=ln(1-0.99/ln(1-[4x104bases/4.7x106bases])=-4.6/-0.01=461clones
Appendix B
Control Fosmid Library Production
The Fosmid Control DNA provided in the kit can be used to test and familiarize the user with all the steps involved in producing a fosmid library.
The Fosmid Control DNA, as provided in the kit, is purified and blunt-ended and ready for ligation to the Cloning-Ready pEpiFOS-5 vector. If desired, the Control can be put through the end-repair and gel purification steps (Parts B, C, D) of the Fosmid Library Production procedure.
1. PrepareEPI100-T1R host cells as described in Part F, Step 1.
2. LigatetheFosmidControlDNAtothepEpiFOS-5vector.
[email protected] •(800)284-8474 11
EpiFOS™ Fosmid Library Production Kit
Combinethefollowingreagentsintheorderlistedandmixaftereachaddition.
3.5 μl sterilewater 1 μl 10XFast-LinkLigationBuffer 1 μl 10mMATP 1 μl pEpiFOS-5Vector(0.5μg/μl) 2.5 μl FosmidControlDNA(100ng/μl) 1 μl Fast-LinkDNALigase 10 μl Totalreactionvolume
3. Incubateatroomtemperaturefor2hours.4. Transferthereactionto70°Cfor10minutestoinactivatetheFast-LinkDNALigase.5. Packagetheentire10μlligationreactionasdirectedinPartF,Steps2-9.6. Titerthepackagedcontrolclonesbymakinga1:1000dilutionofthepackaged
phageextractinPhageDilutionBuffer.Add10μlofthedilutedpackagedphageto100μlofEPI100-T1Rhostcells.Adsorbatroomtemperaturefor20minutes.
7. SpreadtheinfectedEPI100-T1RcellsonLBmedium+12.5μg/mlchloramphenicol.Incubatetheplateovernightat37°Ctoselectforthecontrolfosmidclones.
8. Countthecoloniesanddeterminethetiter,cfu/mlofthereaction(refertoPartG, Step4).Usersshouldexpectapackagingefficiencyof>1x107cfu/ml.
Appendix C
Testing the Efficiency of the MaxPlax Packaging Extracts
Kitcomponentsusedinthisstep:Ligated Lambda Control DNA, MaxPlax Lambda Packaging Extracts, LE392MP Plating Strain.
Additionallyrequired:
LB Plates without antibiotic
LB Top Agar(LBbrothcontaining0.7%[w/v]Bacto-agarsupplementedwith10mMMgSO4)
Phage Dilution Buffer(10mMTris-HCl[pH8.3],100mMNaCl,and10mMMgCl2)
PleaseseetheproductliteraturefortheMaxPlaxLambdaPackagingExtracts,thatisincludedonpage17,fordetailsonhowtotesttheefficiencyoftheextracts.
Appendix D
Amplification and Storage of the Fosmid Library
Short Term Storage: After dilution of the packaging reaction and addition of chloroform, thepackagedfosmidlibrarycanbestoredat4°Cforseveraldays.Forlongertermstorage, see recommendations below.
Long Term Storage: For longer term storage we recommend storage of the packaged DNAasaprimarylibraryorstorageofthelibraryintheEPI300-T1R Phage T1-resistant E. coli plating strain using one of the methods described below.
12 www.epicentre.com
EpiFOS™ Fosmid Library Production Kit
Method A - Storage of Packaged DNA.
1. Tothepackagedfosmidlibrary,addsterileglyceroltoafinalconcentrationof20%, mixandstoreat–70°C.
Method B - Storage of Infected Cells.
1. Adsorbthepackagedphagetobacterialcells(seePartH).
2. Basedontheexpectedtiter,resuspendthecellsinanappropriatevolumeofliquidmedia.
3. Transfer the final resuspension to a sterile tube and add sterile glycerol to a final concentrationof20%.Mixthesolutionandstorealiquots(whichwouldeachconstitutealibraryofthedesiredcoverage)at–70°C.
Method C - Storage of Amplified Library.
1. Adsorbthepackagedphagetobacterialcells(seePartH).
2. Spreadanappropriatevolumeofinfectedbacteriaontoaplate(s)withtheappropriateantibioticandincubateat37°Covernight.
3. Add~2mlofliquidmedia(i.e.,LB)toaplateandresuspendallofthebacterialcells.
4. Transfertheresuspendedcellsandmediatothenextplate(ifmorethanoneovernight plate was used) and repeat resuspension process. Do this for as many plates as desired.
5. Transfer the final resuspension to a sterile tube and add sterile glycerol to a final concentrationof20%.Mixthesolutionandstorealiquots(whichwouldeachconstitutealibraryofthedesiredcoverage)at–70°C.
Appendix E
pEpiFOS-5 Sequencing Primers and Vector Data
pCC1/pEpiFOS-5 Sequencing Primers
Primersareavailableseparately:
pCC1™/pEpiFOS™ Forward Sequencing Primer Cat.No.F5FP010
5′ GGATGTGCTGCAAGGCGATTAAGTTGG 3′ ............1nmolsuppliedinTEBufferat50μM
pCC1™/pEpiFOS™ Reverse Sequencing Primer Cat.No.F5RP011
5′ CTCGTATGTTGTGTGGAATTGTGAGC 3′ ...............1nmolsuppliedinTEBufferat50μM
Note: The sequence of the pCC1/pEpiFOS Forward and Reverse Primers do not function well as IRD800-labeled sequencing primers. We recommend using the T7 and pCC1/pEpiFOS RP-2 Primers instead of the pCC1/pEpiFOS Forward and Reverse Primers respectively, for this purpose.
[email protected] •(800)284-8474 13
EpiFOS™ Fosmid Library Production Kit
pCC1™/pEpiFOS™ RP-2 Reverse Sequencing Primer
5′ TACGCCAAGCTATTTAGGTGAGA 3′
Orientation for Fosmid End-Sequencing
ThefollowingisthenucleotidesequenceofpEpiFOS-5(bases230-501)fromthepCC1/pEpiFOSForwardSequencingPrimer(230-256)tothepCC1/pEpiFOSReverseSequencingPrimer(501-476)encompassingtheT7RNApolymerasepromoter(311-330)and the Eco72Isite(359-364).
230 GGATGTGCTG CAAGGCGATT AAGTTGGGTA ACGCCAGGGT TTTCCCAGTC
280 ACGACGTTGT AAAACGACGG CCAGTGAATT GTAATACGAC TCACTATAGG
330 GCGAATTCGA GCTCGGTACC CGGGGATCCC AC - - Cloned Insert
- - - Cloned Insert - - - - - - GTGGGATC CTCTAGAGTC
380 GACCTGCAGG CATGCAAGCT TGAGTATTCT ATAGTCTCAC CTAAATAGCT
430 TGGCGTAATC ATGGTCATAG CTGTTTCCTG TGTGAAATTG TTATCCGCTC
480 ACAATTCCAC ACAACATACG AG
An electronic copy of the pEpiFOS-5 sequence is available for downloading at our Web site (www.epibio.com/sequences) or can be requested via e-mail ([email protected]) or by calling Technical Service.
14 www.epicentre.com
EpiFOS™ Fosmid Library Production Kit
Figure 1. pEpiFOS™-5 Fosmid Vector
[email protected] •(800)284-8474 15
EpiFOS™ Fosmid Library Production Kit
Enzyme Sites Location Acc65I 2 344,4586AclI 2 1133,4978Afe I 1 3945AflII 2 5987,6227AflIII 3 4352,4526,6861AgeI 3 3206,4436,5329AhdI 1 6865AleI 1 5922Apa I 1 6351ApaBI 3 96,1946,7025ApaLI 1 87BamHI 2 353,365BbsI 3 4429,4618,5495BclI 1 5177BfuAI 3 390,3393,7160BglI 3 651,2550,6999BglII 2 2525,4592BlpI 1 3858Bme1580I 3 91,755,6351BmgBI 2 4416,7176BmrI 3 268,6397,6526Bpu10I 3 1446,3306,4501BsaI 1 6189BsaBI 2 7133,7217BsaHI 1 146BseYI 2 5269,6026BsmI 2 824,1231BsmBI 3 994,1547,3321BspEI 2 1222,5146BspLU11I 1 6861BspMI 3 390,3393,7160BsrBI 3 476,1660,2282BsrG I 1 3159BssHII 2 4843,5387BssSI 3 4536,6186,6749BstAPI 3 95,1945,7024BstEII 1 6983BstX I 1 4464BstZ17I 1 1844BtsI 2 570,4938DraIII 2 1945,7202EagI 2 2,643Eco47III 1 3945Eco72 I 1 361EcoNI 1 2848EcoO109I 2 1728,7237EcoRI 1 332
Enzyme Sites Location EcoRV 2 3507,3736FspI 3 167,3131,6957HindIII 1 395HpaI 1 7008KpnI 2 348,4590Mfe I 1 4366MscI 2 955,4797NaeI 2 3084,7000Nar I 1 146NcoI 2 917,6566NdeI 2 94,4384NgoMIV 2 3082,6998NotI 2 2,643NruI 2 1644,7053NspI 3 393,1831,6865PaeR7I 1 2392PciI 1 6861PflFI 1 4650Pml I 1 361PpuMI 2 1728,7237PsiI 1 2501PspOMI 1 6347PstI 3 387,3404,4945PvuI 2 188,5252SalI 3 377,657,7041SapI 2 3982,5192SbfI 2 387,3404ScaI 1 805SexAI 1 6979Sfi I 1 651SfoI 1 147SgrAI 2 4436,5593SimI 2 4550,7237SmaI 3 350,651,2872SnaBI 1 5010SpeI 1 6101Sph I 1 393Srf I 1 651Sse8647I 1 1728StuI 1 2553TatI 3 77,803,3159TliI 1 2392Tth111I 1 4650XbaI 2 371,2571XhoI 1 2392XmaI 3 348,649,2870
Restriction Analysis of the pEpiFOS-5 Vector
Restriction Enzymes that cut pEpiFOS-5 1 to 3 times:
16 www.epicentre.com
EpiFOS™ Fosmid Library Production Kit
Aat IIAsc IAsiS IAvr IIBbvC I
BciV IBfrB IBsiW IBspD IBstB I
Bsu36 ICla IFse IMlu INhe I
Nsi IPac IPme IRsr IISac II
SanD ISwa IXcm ITsp509I
Restriction Enzymes that do not cut pEpiFOS-5:
Acc IAci IAlu IAlw IAlwN IApo IAse IAva IAva IIBan IBan IIBfa IBsaA IBsaJ IBsaW IBsiE IBsiHKAIBsl IBsmA I
Bsp1286IBspHIBsr IBsrD IBsrF IBssK IBstDS IBstF5 IBstN IBstUIBstY IBtg ICac8ICviJ IDde IDpn IDra IDrd IDsa I
Eae IEar IFau IFnu4HIGdi IIHaeIHaeIIHaeIIIHhaIHincIIHinfIHinPIHpaIIHphIHpy188IHpy99IHpyCH4IIIHpyCH4IVHpyCH4V
Mae IIMae IIIMbo IMbo IIMly IMnl IMse IMsl IMsp IMspA1 IMwo INci INla IIINla IVPflMIPle IPshA IPspG IPvu II
Rsa ISac ISau3A ISau96 IScrF ISfaN ISfc ISml ISsp ISty ITaq ITfi ITse ITsp45 ITsp4C ITsp509ITspR IXmn I
Restriction Enzymes that cut pEpiFOS-5 4 or more times:
[email protected] •(800)284-8474 17
MaxPlax™ Lambda Packaging Extracts
MaxPlax™ Lambda Packaging Extracts Protocol
(This protocol is also available as product literature #65 and is provided with Cat. Nos. MP5105, MP5110, and MP5120)
1. IntroductionMaxPlax™LambdaPackagingExtractsareaconvenient,high-efficiencysystemdesignedfor in vitro lambdapackagingreactions.MaxPlaxLambdaPackagingExtractsaresuppliedas predispensed single-tube reactions that have been optimized for packaging of methylatedandunmethylatedDNA.Thepackagingextractsroutinelyyieldpackagingefficienciesof>1x109pfu/μgofControlλDNA.Theextractscanbeusedintheconstruction of representative cDNA libraries and genomic cloning of highly modified (methylated) DNA into λ-phage or cosmid vectors.
TraditionalpackagingextractsarederivedfromtwocomplementarylysogenicE. coli strains,BHB2690andBHB2688,asdescribedbyHohn(1979).5TheMaxPlaxextractsutilizeanewpackagingstrain,NM759*,reportedbyGunther,MurrayandGlazer(1993).6 Thisstrain,whichreplacesstrainBHB2690inthepreparationofthesonicationextract,isarestriction-freeK12-derivedstraindeficientintheproductionofλ-phagecapsidproteinD.Whencombinedwiththecomplementaryfreeze-thawextractfromstrainBHB2688**,5 deficientintheproductionofλ-phagecapsidproteinE,anextremelyhigh-efficiencyofpackaging for λ DNA is obtained. Moreover, the ability to package λ DNA bearing the mammalian methylation pattern is greatly enhanced, as evidenced by the high efficiency of λ-vector rescue from transgenic mouse DNA.6 The lack of restriction activity has been shown to be crucial for the high efficiency rescue of lambda shuttle vectors from transgenic mouse DNA.6,7
*NM759: [W3110 recA56, ∆(mcrA) e14, ∆(mrr-hsd-mcr), (λimm434, clts, b2, red3, Dam15, Sam7)/λ]
**BHB2688: [N205 recA–, (λimm434 clts, b2, red3, Eam4, Sam7)/λ]
Store the MaxPlax Lambda Packaging Extracts at –70°C or below. Exposure to higher temperature will decrease packaging efficiencies.
2. Product SpecificationsStorage:StorethecontrolhostbacteriaandtheMaxPlaxLambdaPackagingExtractsat–70°C.Exposuretohighertemperatureswillgreatlycompromisepackagingextractefficiency. Avoid long term storage of product in the presence of dry ice. Once removed fromthefoilpackage,avoidanyexposuretodryice.Storetheremainderofthekitcomponentsat–20°C.Afterthawing,storetheControlDNAat4°C.
Storage Buffers:MaxPlaxLambdaPackagingExtractsaresuppliedasunlabeledsingletubesoffreeze-thaw/sonicateextracts.Controlplatingbacteriaaresuppliedasaglycerolstock. Control ligated λ DNA is supplied in 1X Ligation Buffer.
18 www.epicentre.com
MaxPlax™ Lambda Packaging Extracts
Guaranteed Stability:MaxPlaxLambdaPackagingExtractsareguaranteedtomaintainapackagingefficiencyof>1.0x109pfu/μgofcontrolλDNA,whenstoredasdirectedforone year from the date of purchase.
3. Related ProductsThefollowingproductsarealsoavailable:
− pWEB-TNC™ Cosmid Cloning Kit− pWEB™ Cosmid Cloning Kit− EpiFOS™ Fosmid Library Production Kit− Lambda Terminase
4. Protocol for Packaging Lambda DNAThisprotocolcanbeusedforthepositivecontrolreactionaswellasforexperimentalreactions. The positive control reactions must be plated on the control host bacterial strain(LE392MP)includedwiththeMaxPlaxExtracts.Theproperbacterialplatingstrainfortheexperimentalreactionswillvarydependingonthecloningvectorused.Seethe vector manufacturer’s recommendations for the proper strain and plating media requirements.Ligationreactionsmaybeaddeddirectlytothepackagingextracts.Whendoingso,itisimportantto:a)addavolumeof10μlorlesstothepackagingreaction,andb)heatinactivatetheligase(i.e.,treatmentat65°Cfor15minutes)asactiveDNAligase will decrease packaging efficiencies.
Solutions:
Phage Dilution Buffer LB Broth (1 Liter) LB Plates 10mM Tris-HCl(pH8.3) 10g Bacto-tryptone LBBrothwith1.5%(w/v)100mM NaCl 5g Bacto-yeastextract Bacto-agar 10mM MgCl2 10g NaCl LB Top Agar AdjustpHto7.0withNaOH LBBrothwith0.7%(w/v) Bacto-agar Plating Bacteria Preparation:
1. Thedaybeforeperformingthepackagingreactions,inoculate50mlofsupplemented(10mMMgSO4) LB broth with a single colony of the plating bacterial strainandshakeovernightat37°C.
2. Thedayofthepackagingreactions,inoculate50mlofsupplemented(10mMMgSO4+0.2%maltose)LBbrothwith5mloftheovernightcultureandshakeat37°Ctoan OD600=0.8-1.0.Storethecellsat4°Cuntilneeded;cellsmaybestoredforupto72hours.
Packaging Reactions:1. Thawtheappropriatenumberofpackagingextractsatroomtemperature.Forevery
twopackagingreactions,thawoneextractthenplaceonice.
2. Whenthawed,immediatelytransferhalf(25μl)ofeachpackagingextracttoa
[email protected] •(800)284-8474 19
MaxPlax™ Lambda Packaging Extracts
second 1.5-ml tube and place on ice.
3. AddthesubstrateDNA(10μl[0.2μg]ofthecontrolDNA)toatubecontaining 25μlofextract.Ifperforminganoddnumberofpackagingreactions,theremaining25μlofextractcanberefrozenat–70°C.
4. Mixbypipettingseveraltimes;avoidtheintroductionofairbubbles.Returnallofthe contents to the bottom of the tube by brief centrifugation if necessary.
5. Incubatethereaction(s)at30°Cfor90minutes.
6. Attheendofthisincubation,addtheadditional25μlofthawedextracttoeachreactiontubeat30°C(Ifperformingtwopackagingreactions,thawanothertubeofextractandadd25μltoeachtube.)andincubatethereaction(s)foranadditional 90minutesat30°C.
7. Add500μlofphagedilutionbufferandmixbygentlevortexing.
8. Add25μlofchloroformandmixbygentlevortexing(storeat4°C).
9. Assaythepackagedphagebytiteringontheappropriatebacterialstrain(LE392MPfor the control).
Titering Phage Extracts:
1. Makeserialdilutionsofthepackagedphageinphagedilutionbuffer.Use10-5 and 10-6 dilutions for the control reactions.
10-2dilutionis10μlofpackagedphageparticlesinto990μlofphagedilutionbuffer;vortexmix.
10-4dilutionis10μlof10-2dilutioninto990μlphagedilutionbuffer;vortexmix.
10-5dilutionis100μlof10-4dilutioninto900μlphagedilutionbuffer;vortexmix.
10-6dilutionis10μlof10-4dilutioninto990μlphagedilutionbuffer;vortexmix.
2. Add100μloftheappropriateserialdilutionsto100μlofpreparedplatingbacteria(useLE392MPforthecontrolreactions)andincubatefor15minutesat37°C.
3. Add3.0mlofmeltedsupplemented(10mMMgSO4)LBtopagar(cooledto~48°C).Vortexgentlyandpourontopre-warmed(37°C)LBplates.Allowthetopagartosolidifyandthenincubateovernightat37°C.
4. Counttheplaquesanddeterminethetiter(pfu/ml)andpackagingefficiency(Seesample calculations).
Sample Calculations:
Iftherewere110plaquesona10-6dilutionplate,thenthetiter,pfu/ml,(wherepfurepresentsplaqueformingunits)ofthisreactionwouldbe:
(#ofplaques)(dilutionfactor)(1000μl/ml) (110pfu)(106)(1000μl/ml) ___________________________________ OR ______________________ =1.1x109pfu/ml (volumeofphageplated[μl]) (100μl)
20 www.epicentre.com
MaxPlax™ Lambda Packaging Extracts
Thepackagingefficiency(pfu/μgDNA)ofthisreactionwouldbe:
(#ofplaques)(dilutionfactor)(totalreactionvol.) (110pfu)(106)(550μl)________________________________________ OR ____________________ =3x109pfu/μg(vol.ofdilutionplated)(amountofDNApackaged) (100μl)(0.2μg)
5. References1. Fiandt,M.(1998)Epicentre Forum 5 (3), 1.
2. Sambrook,J.et al.,(1989)in:Molecular Cloning: A Laboratory Manual (2nd ed.), CSHLaboratoryPress,NewYork.
3. Wahl, G.M. et al.,(1987)Proc. Natl. Acad. Sci. USA 84,2160.4. DiLella,A.G.andWoo,S.L.C.(1987)Meth. Enzymol. 152, 199.
5. Hohn,E.G.(1979)Methods Enzymol. 68,299.6. Gunther, E.G. et al., (1993) Nucl. Acids Res. 21,3903.7. Kohler,S.W.et al.,(1990)Nucl. Acids Res. 18,3007.8. Kim,U.J.et al.,(1992)Nucl. Acids Res. 20,1083.9. Birren, B. et al., (1999) Construction of Bacterial Genomic Libraries in Genome
Analysis: A Laboratory Manual v. 3, 3.
10. Birren,B.et al., (1999), Cosmids in Genome Analysis: A Laboratory Manual v. 3,87.
EPI100, EpiFOS, EZ-Tn5, Fast-Link, Fast-Screen, GELase, MasterPure, MaxPlax, Plasmid-Safe, pCC1, pEpiFOS, and pWEB are trademarks of Epicentre, Madison, Wisconsin.
SYBR is a registered trademark of Molecular Probes, Inc., Eugene, Oregon.
Dark Reader is a trademark of Clare Chemical Research, Denver, Colorado.
DyNA Quant is a trademark of Hoefer Pharmacia Biotech, San Francisco, California.
Visitourtechnicalblog:epicentral.blogspot.com