Designation:D6734−01(Reapproved2009)StandardTestMethodforLowLevelsofColiphagesinWater1ThisstandardisissuedunderthefixeddesignationD6734;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1ThistestmethodcoversthedeterminationofcoliphagesinfectiveforE.coliCinwater.Thetestmethodissimple,inexpensive,andyieldsanindicationofwaterqualitywithin6.5h.Thiscoliphagemethodcandeterminecoliphagesinwaterdownto1coliphagepervolumeofwatersampled.1.2Thetestmethodisapplicabletonaturalfreshwatersamplesandtosettled,filteredorfinishedwatersamples.1.3ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D1129TerminologyRelatingtoWaterD1193SpecificationforReagentWaterD3370PracticesforSamplingWaterfromClosedConduitsD4201TestMethodforColiphagesinWater(Withdrawn2005)33.Terminology3.1Fordefinitionsoftermsusedinthistestmethod,refertoTerminologyD1129.3.2DefinitionsofTermsSpecifictoThisStandard:3.2.1bacteriallawn,n—confluentgrowthofbacteriacul-turedonanagarplate.3.2.2coliphage,n—bacterialviruscapableofplaquingonthewide-rangeE.colihoststrainusedinthisassay.3.2.3plaque,n—thecircularzoneofclearing(lysis)ofthevisiblegrowthofbacteriaonaoneortwolayeragarplate,causedbytheactionofoneormorebacteriophage.3.2.4plaqueformingunit(PFU),n—thetermusedtoreportthenumberofplaquesformedonanagarcultureplatepreviouslyseededwithamicroorganismsusceptibletoabacteriophage.Althoughtheoretically,eachplaquedevelopsfromtheactionofasinglebacteriophage,microbiologistsusetheterm,PFU,toackno...
