4.1.2.4	-20°C, stable for 1 year	
4.1.2.4	25°C, up to 15 days, the enzyme directly immobilized through ionic exchange interactions on oxidized multiwalled carbon nanotubes retains almost the full activity. The soluble enzyme shows a decrease of activity after the first 5 days, thereby reaching a value of ca. 80% of residual activity after 15 days	
4.1.2.4	4°C, 80 days, the residual activity of the enzyme immobilized on glutaraldehyde-(3-aminopropyl)triethoxysilane nano-magnet material, and of the enzyme immobilized on glutaraldehyde-(3-aminopropyl)triethoxysilane nano-magnet material, is 77.5%, 1.85 times better than that of the soluble enzyme	
4.1.2.4	4°C, in ammonium sulfate solution, stable	
4.1.2.4	4°C, stable for 1 month