Designation:E2805−11StandardPracticeforMeasurementoftheBiologicalActivityofRicin1ThisstandardisissuedunderthefixeddesignationE2805;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.INTRODUCTIONRicinisamemberoftheproteintoxinsthatcausetheirphysiologicaleffectbyinactivationofribosomes.Ricinisamemberoftheclass2ribosomeinactivatingproteins(1).2OthermembersofthisclassoftoxinsincludetheproteinsabrinandShigatoxin.Ricinconsistsoftwochains,theA-chainthatisresponsiblefortheN-glycosidaseenzymaticactivityandtheB-chainthatisneededforcellbindingandintra-cellularprocessing.Ricinisaheterogeneousproteinwithmolecularweightsrangingfromapproximately62to64kilodaltons(kDa)(2).Bothchainsareglycosylatedandofsimilarsize(approximately32kDa).Thereareseveralgenesencodingputativericinandricin-likeproteinsinthegenomeofR.communis(3)resultingindifferencesintheaminoacidsequenceofthesubunits.Thedifferencesinaminoacidsequenceandglycosylationbothcontributetotheheterogeneityofricin.1.Scope1.1Thisguideisintendedforthemanufacturersandusersofricinreferencematerial.Ricinreferencematerialsarewell-characterizedmaterialsthatcanbeusedtotestdetectiondevicesandcalibratelaboratorymeasurements.Itisanticipatedthatricinreferencematerialswillbecharacterizedbybio-chemicalmethodsinadditiontothemeasurementofbiologicalactivity.1.2Thispracticedetailsthemeasurementofricinbiologicalactivityusingacell-freetranslation(CFT)assay(4).1.3TheCFTassayhasbeendevelopedforuseinanybiotechnologylaboratorywheredeterminationorconfirmationofricinbiologicalactivityisrequired.1.4TheCFTassayhasbeenvalidatedbytheU.S.ArmyMedicalResearchInstituteofInfectiousDiseases(USAM-RIID)VP-016ValidationofCell-FreeTranslationAssayfortheDetectionofRicinToxinBiologicalActivitiesincompli-ance(5)withGoodLaboratoryPractices(GLP)RegulationsoftheFoodandDrug...
