Designation:E1880−12StandardPracticeforTissueCryosectionAnalysiswithSIMS1ThisstandardisissuedunderthefixeddesignationE1880;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1ThispracticeprovidestheSecondaryIonMassSpec-trometry(SIMS)analystwithamethodforanalyzingtissuecryosectionsintheimagingmodeoftheinstrument.Thispracticeissuitableforfrozen-freeze-driedandfrozen-hydratedcryosectionanalysis.1.2Thispracticedoesnotdescribemethodsforoptimalfreezingofthespecimenforimmobilizingdiffusiblechemicalspeciesintheirnativeintracellularsites.1.3Thispracticedoesnotdescribemethodsforobtainingcryosectionsfromafrozenspecimen.1.4Thispracticeisnotsuitableforanyplasticembeddedtissues.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2E673TerminologyRelatingtoSurfaceAnalysis(Withdrawn2012)33.Terminology3.1Definitions:3.1.1SeeTerminologyE673fordefinitionsoftermsusedinSIMS.4.SummaryofPractice4.1ThispracticedescribesamethodfortheanalysisoftissuecryosectionswithSIMS.TissuecryosectionsforSIMSanalysisneedtobemountedflatonanelectricallyconductingsubstrate.CryosectionsshouldremainflatandadherewelltothesubstrateforSIMSanalysis.Thisisachievedbypressingfrozencryosectionsintoanindiumsubstrate.Indium,beingamalleablemetal(Mohhardness=1.2,Young’smodulus=10.6GPa),providesa“cushion”forpressingandholdingthefrozencryosectionsflatforSIMSanalysis.Indiumsubstratesarepreparedbypressingsheetindiumontoapolishedsiliconwafer.Anapproximately1µmthicklayerofindium(99.999%purity)isthenvapordepositedonthissurface.Thistoplayerprovides“fluffy”indiumthathelpsinholdingcryosec...
