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AAT Bioquest/Fura FF,AM【Fura-2FF,AM】*CAS号348079-12-9*/21027/10x50微克
Overview | PrinterFriendlyVersion |
Ex/Em(nm) | 363/512 |
MW | 1023.80 |
CAS# | 348079-12-9 |
Solvent | DMSO |
Storage | F/D/L |
Category | GPCR CalciumGPCRAssays |
Related | CalciumChannels pHandIonIndicators BiochemicalAssays |
Spectrum | AdvancedSpectrumViewer |
UseofCalciumindicatorAMEsters
1.LoadCellswithCalciumIndicatorAMEsters:
AMestersarethenon-polarestersthatreADIlycrosslivecellmembranes,andrapidlyhydrolyzedbycellularesterasesinsidelivecells.AMestersarewidelyusedforloadingavarietyofpolarfluorescentprobesintolivecellnon-invasively.However,cautionsmustbeexcisedwhenAMestersareusedsincetheyaresusceptibletohydrolysis,particularlyinsolution.Theyshouldbereconstitutedinhigh-quality,anhydrousdimethylsulfoxide(DMSO).DMSOstocksolutionsshouldbestoreddesiccatedat-20°Candprotectedfromlight.Undertheseconditions,AMestersshouldbestableforseveralmonths.
FollowingisourrecommendedprotocolforloadingAMestersintolivecells.Thisprotocolonlyprovidesaguideline,andshouldbemodifiedaccordingtoyourspecificneeds.
a) Preparea2to5mMAMestersstocksolutioninhigh-quality,anhydrousDMSO.
b) Onthedayoftheexperiment,eitherdissolvecalciumindicatorssolidinDMSOorthawanaliquotoftheindicatorstocksolutionstoroomtemperature.Prepareaworkingsolutionof2to20µMinthebufferofyourchoice(suchasHanksandHepesbuffer)with0.04%Pluronic®F-127.Formostcelllineswerecommendthefinalconcentrationofcalciumindicatorsbe4-5uM.Theexactconcentrationofindicatorsrequiredforcellloadingmustbedeterminedempirically.Toavoidanyartifactscausedbyoverloadingandpotentialdyetoxicity,itisrecommendedtousetheminimalprobeconcentrationthatcanyieldsufficientsignalstrength.
Note:ThenonionicdetergentPluronic®F-127issometimesusedtoincreasetheaqueoussolubilityofcalciumindicatorAMesters. AvarietyofPluronic®F-127solutionscanbepurchasedfromAATBioquest.
c) Ifyourcells(suchasCHOcells)containingtheorganicanion-transports,probenecid(2–5mM)orsulfinpyrazone(0.2–0.5mM)maybeaddedtothethedyeworkingsolution(finalinwellconcentrationwillbe1-2.5mMforprobenecid,or0.1-0.25mMforsulfinpyrazone)toreducetheleakageofthede-esterifiedindicators.
Note:AvarietyofReadiUse™probenecidincludingwatersolublesodiumsaltandstABIlizedsolutioncanbepurchasedfromAATBioquest
d) Addequalvolumeofthedyeworkingsolution(fromStepborc)intoyourcellplate.
e) Incubatethedye-loadingplateroomattemperatureor37°Cfor20minutes(especiallyFluo-8AM)to2hours,andthenincubatetheplateatroomtemperatureforanother30minutes.
Note1:Decreasingtheloadingtemperaturemightreducethecompartmentalizationoftheindictor.
Note2:IncubatetheCal-520AMlongerthan2hoursgivesbettersignalintensityforsomecelllines.
f) ReplacethedyeworkingsolutionwithHHBSorbufferofyourchoice(containingananiontransporterinhibitor,suchas1mMprobenecid,ifapplicable)toremoveexcessprobes.
g) RuntheexperimentsatdesiredEx/Emwavelengths(seeTable1).
2.MeasureIntracellularCalciumResponses:
Figure1.ResponseofendogenousP2YreceptortoATPinCHO-M1cellswithoutprobenecid.CHO-M1cellswereseededovernightat40,000cellsper100µLperwellina96-wellblackwall/clearbottomcostarplate.100µlof4µMFluo-3AM,Fluo-4AMorCal520®AMinHHBSwereaddedintothewells,andthecellswereincubatedat37°Cfor2hour.Thedyeloadingmediumwerereplacedwith100µlHHBS,50µlof300µMATPwereadded,andthenimagedwithafluorescencemicroscope(OlympusIX71)usingFITCchannel.
A B
Figure2.ATP-stimulatedcalciumresponseofendogenousP2YreceptorinCHO-K1cellsmeasuredwithCal-520®orFluo-4AM.CHO-K1cellswereseededovernightin50,000cellsper100µLperwellina96-wellblackwall/clearbottomcostarplate.100µLof5µMFluo-4AMortheCal-520®AMwith(A)orwithout(B)2.5mMprobenecidwasaddedintothecells,andthecellswereincubatedat37oCfor2hours. ATP(50µL/well)wasaddedbyFlexStation(MolecularDevices)toachievethefinalindicatedconcentrations.
UseofCalciumindicatorSalts
TodetermineeitherthefreecalciumconcentrationofasolutionortheKdofasingle-wavelengthcalciumindicator,thefollowingequationisused:
[Ca]free=Kd[F-Fmin]/Fmax-F]
WhereFisthefluorescenceoftheindicatoratexperimentalcalciumlevels,FministhefluorescenceintheabsenceofcalciumandFmaxisthefluorescenceofthecalcium-saturatedprobe.Thedissociationconstant(Kd)isameasureoftheaffinityoftheprobeforcalcium.TheCa2+-bindingandspectroscopicpropertiesoffluorescentindicatorsvaryquitesignificantlyincellularenvironmentscomparedtocalibrationsolutions.InsitucalibrationsofintracellularindicatorstypicallyyieldKdvaluessignificantlyhigherthaninvitrodeterminations.InsitucalibrationsareperformedbyexposingloadedcellstocontrolledCa2+buffersinthepresenceofionophoressuchasA-23187,4-bromoA-23187andionomycin.Alternatively,cellpermeabilizationagentssuchasdigitoninorTriton®X-100canbeusedtoexposetheindicatortothecontrolledCa2+levelsoftheextracellularmedium.TheKdvaluesofsomecalciumreagentsarelistedinTable1foryourreference.
UseofCalciumindicatorConjugates
Comparedtothefreeionindicator,dextranconjugatesofthesesameindicatorsexhibitbothreducedcompartmentalizationandmuchlowerratesofdyeleakage.Sincethemolecularweightofthedextran,netcharge,degreeoflabeling,andnatureofthedyemayaffecttheexperiment,researchersareadvisedtoconsulttheprimaryliteratureforinformationspecifictotheapplicationofinterest.
References&Citations | CitationExplorer |
AnessentialroleofNAD(P)Hoxidase2inUVA-inducedcalciumoscillationsinmastcells
Authors:ZhiYingLi,WenYiJiang,ZongJieCui
Journal:Photochemical&PhotoBIOLOGicalSciences(2015):414--428
Lastinginhibitionofreceptor-mediatedcalciumoscillationsinpancreaticacinibyneutrophilrespiratoryburst--Anovelmechanismforsecretoryblockadeinacutepancreatitis?
Authors:HuiYuanLiang,ZhiMinSong,ZongJieCui
Journal:Biochemicalandbiophysicalresearchcommunications(2013):361--367