DescriptionCatalogueNumberAG400ReplacesAG390TradeNameBLACK-GOLDDescriptionBLACK-GOLD®IIStainOverviewBlack-Gold®IIstainisanaurohalophosphatecomplexwhichstainsspecificallyformyelinwithinthecentralnervoussystem.Black-GoldIIstainingprovideshighresolution,highcontrast,ashorthistochemicalprocessingtime,andhighreproducibility.Black-GoldIIstainisanewandimprovedversionofitspredecessor,Black-Goldstain(discontinued).TheadvantagesofMillipore’sBlack-GoldIIoverBlack-GoldIstainarethatitismorereADIlysoluble,canbeutilizedatahigherconcentration,producesamoreuniformandconsistentstaining,takeslesstimetostain,anddoesnotrequirepost-stainingintensificationsteps.TheuseofBlack-GoldIIstainistailoredtostudiesusingformalin-fixed,non-solventprocessedtissue.Thetechniquestainslargemyelinatedtractsdarkred-brown,whiletheindividualmyelinatedfibersappearblack.Thisnoveltracercanbeusedtolocalizebothnormalandpathologicalmyelin.Black-GoldIIstaincandemonstrateandcharacterizespecificmyelinchangesassociatedwithexposuretodiverseneurotoxicantsincludingkainicacid,methamphetamine,acrylamide,domoicacid,3-nitropropionicacid,Fluoro-Gold™tracerandisoniazid.BlackGoldIIPurity:Nodetectableamountofuncomplexedgoldwasfound.BlackGoldIIIllumination:Brightfieldordarkfield.BlackGoldIISolubility:Freelysolubleinwater,saline,ordiluteacids.ProductInformationComponentsBlack-GoldII:150mgdrypowder,yellowincolor.PresentationSeeComponentsStorageandShippingInformationStorageConditionsThekitcanbestoredatroomtemperature.Ideally,theBlack-GoldIIpowdershouldbekeptinadesiccator,becauseofitshygroscopicnature.Thedrypowder,ifunopenedandstoredproperly,isusableforuptooneyearfromdateofreceipt.OnceresUSPendedtheBlack-GoldIIstainingsolutionshouldbestoredinthedarkat4°Candisgoodforupto3months.TOXICITY:Althoughthecompoundappearstobeoflowtoxicity,ithasnotbeenextensivelyevaluatedandthereforeroutinelaboratorycautionshouldbeexercised.Notintendedforhumanconsumption.ApplicationsKeyApplicationsImmunohistochemistryApplicationNotesTissueFixation:Tissuecanbefixedwitheitherformalinor4%PFA.Typicallyanimalsareperfusedwithneutralphosphatebuffered10%formalin(or4%formaldehyde)viatheascendingaorta.Thebrainsarethenremovedandfixedovernightinthesamefixativesolution.Longerfixationtimesaregenerallynotrecommended.Forcryosections,thebrainsmaybeprotectedthroughtreatmentwithsucrosesolution(20-30percent).Subsequentlyfrozenbraintissueiscutonafreezingslidingmicrotome.Note:Black-GoldIIwillnotstainparaffinembeddedorunfixedtissue.Sectioning:Eitherfrozenorfixed,non-frozenvibratomesectionscanbeusedandshouldbecutatathicknessof20-40μm.Thesectionsarethentypicallymountedonpositivelychargedslides.Thesectionscanalsobestainedloose,althoughthesectionsareeasiertohandlewhenmountedonslides.Solutions:Black-GoldIIpowdershouldberesuspendedwithsalinesolution(0.9%NaCl)toafinalconcentrationof0.3%.Simplyaddthe150mgofBlack-GoldIIpowderinto50mlsof0.9%NaClsolutionandmixtoresuspend.OnceresuspendedtheBlack-GoldIIstainingsolutionshouldbestoredinthedarkat4°Candisgoodforupto3months.Staining:1)Formalin-fixed,non-embeddedtissuesectionsarefirstmountedfromdistilledwaterontogelatin-coatedslidesandthenairdriedat50-60ºCforatleast½houronaslidewarmer.2)TissuesectionsarethenrehydratedindistilledMilli-Q®waterforabout2minutes.3)Theslidesarethentransferredtoa0.3%Black-GoldIIsolutiondissolvedin0.9%salinevehicleandheatedto60-65ºC.Afterabout12minutes,microscopicmonitoringoftheextentofthelabelingisrecommended.Thismonitoringshouldberepeatedevery2-3minutesuntilthedesireddegreeofmyelinimpregnationisobserved(seebelow).4)Rinsetheslidesforabout2minindistilledMilli-Qwater.5)Transfertheslidestoa1%sodiumthiosulfatesolutionfor3minutes.6)Rinsetheslideswitheitherthree,fiveminchangesoftapwateror15minsofrunningtapwater.Post-stainingsteps:7)Dehydratesectionseitherviagraduatedalcoholicsolutionsorbyairdryingonaslidewarmer.8)Immersesectionsfor1-2mininxyleneorhistoclearandthencoverslipwithanon-polarmountingmedia.BIOLOGicalInformationPhysicochemicalInformationDimensionsMaterialsInformationMaterialsInformation