Pemcdlm amldase was coupled to a penodate-oxrdtsed dextran by reducttve alkylatron m the presence of sodmm cyanoborohydnde A loss of acttvtty (25%) was observed but the conIugate enzyme dextran was more thermostable than the native enzyme Native and dextran-conjugated pemctlhn am&se were rmmobthsed on ammo acttvated sthca (Promaxon, Spherostl, Aerostl) by a classical method usmg ~ut~aldehyde for the nattve enzyme and reducttve alkylatton for the mod&cd enzyme Good relanve acttvrty of the enzymes was obtained after ln~lubill~tion Immobthsatton of both native and mod&d enzymes resulted m the the~ostablhsatlon of the pemcdhn amtdase Enzyme stabrhsatton, Enzyme tmmobthsatton, Pemcdhn amrdase, (Escherrchm co/i)