Aurosphere Carboxylic Acid, Superparamagnetic BeadsAvailable in 2 mL, 5 mL, 10 mL, 50 mL and 100 mL volumes. For bulk pricing, please contact us. The Magnostics Aurosphere Carboxylic Acid beads are superparamagnetic beads coated with carboxyl layer. They have high magnetization in the external magnetic field allowing fast magnetic separation. Aurosphere Carboxylic Acid beads are very versatile and can be used to covalently bond a wide variety of protein and antibodies through carbodiimide chemistry