Theconcentrationofcalciumfoundinclassicmediaandtheirderivativesvariesfrom0inBGJbMediumFitton-JacksonModification,developedtoculturecartilagenousembryonicbone,to2mMinMCDBmedia201,developedtocultureChickEmbryoFibroblasts,anattachedcellline.Asageneralrule,thehighestconcentrationsofcalciumarefoundinserumsupplemented,suchasFBS,classicmediadevelopedforattachedcelltypes.Seragenerallyprotectscellsfromoxidativedamage.Calciumlevelsaregenerallylowerinserum-freemediaandmediadevelopedforprimaryandclonalcellculture.ThismaybeduetothefactthatprimarycellsandcellsgrownatclonaldensitiesaresusceptIBLetothetoxicinfluxofcalciumthroughcellmembranesdamagedbyoxidativeprocesses,prevalentinserum-freeculturemedia,andenzymaticandmechanicalprocessing.Sincecalciumaffectscellsignalinganddifferentiationaswellascellattachment,mediadevelopedforspecificcelltypesmayrequiresubstantiallyloweredcalciumlevels.