▁ ▁Me as uring ▁of ▁the ▁activity ▁of ▁released ▁int rac ell ular ▁en zym es : ▁dead ▁cells ▁release ▁en zym e ▁( e . g . ▁L D H ▁or ▁G AP D H ) ▁and ▁addition ▁of ▁its ▁substr ate ▁leads ▁to ▁color ▁change , ▁that ▁is ▁usually ▁quant ified ▁as ▁change ▁of ▁abs orb ance ▁or ▁l umin isc ence . ▁ ▁Dead ▁cells ▁st aining : ▁a ▁( flu ores cent ) ▁d ye ▁gets ▁inside ▁the ▁dead ▁cells ▁through ▁their ▁dam aged ▁pl asma ▁memb rane . ▁For ▁instance ▁prop id ium ▁i od ide ▁bind s ▁to ▁DNA ▁of ▁dead ▁cells ▁and ▁flu ores cent ▁signal ▁is ▁measured ▁by ▁flow ▁c yt ometry . ▁ ▁H LA ▁typing ▁and ▁cross match ▁test ▁ ▁CD C ▁ass ays ▁are ▁used ▁to ▁find ▁a ▁suitable ▁don or ▁for ▁organ ▁or ▁b one ▁mar row ▁trans plant ation , ▁namely ▁don or ▁with ▁matching ▁phen ot ype ▁of ▁h isto compat ibility ▁system ▁H LA . ▁At ▁first , ▁H LA ▁typing ▁is ▁done ▁for ▁patient ▁and ▁don or ▁to ▁determine ▁their ▁H LA ▁phen ot ypes . ▁When ▁potentially ▁suitable ▁couple ▁is ▁found , ▁cross match ▁test ▁is ▁done ▁to ▁exclude ▁that ▁patient ▁produces ▁don or - specific ▁anti - H LA ▁ant ib od ies , ▁which ▁could ▁cause ▁gra ft ▁re jection . ▁ ▁CD C ▁form ▁of ▁H LA ▁typing ▁( other ▁words ▁ser olog ic ▁typing ) ▁uses ▁batch ▁of ▁anti - H LA