Since its inception a decade ago, sol-gel encapsulation has opened up an intriguing new way to immobilize biological materials. An array of substances, including catalytic antibodies, DNA, RNA, antigens, live bacterial, fungal, plant and animal cells and whole protozoa, have been encapsulated in silica, metal-oxide, organosiloxane and hybrid sol-gel polymers. The advantages of these 'living cer...