Computer hard drive capacity could be revolutionised thanks to the use of a hollow core protein filled with ferritin and a magnetic cobalt-platinum alloy.

A British company called Nanomagnetics has told the New Scientist that the protein apoferritin, the main molecule in which iron is stored in the body, can be manipulated to create a material consisting of magnetic particles each just a few nanometres in diameter.

Each particle can store a bit of information and together they can be packed onto a disk drive at much greater density than is possible using existing hard disk manufacturing methods.

'It provides the hard drive industry with a roadmap to go from pretty near the nano-scale to the ultimate extent of magnetic recordings,' explained Eric Mayes, chief executive of Nanomagnetics.

The process developed by Nanomagnetics involves treatment with an acid solution to remove the iron core from ferritin.

This is followed with a second solution that fills the cores with a magnetic cobalt-platinum alloy.

The resulting solution, called DataInk, is then sprayed onto the surface of a hard disk and treated with heat, altering the crystalline structure of each particle and encouraging them to self-assemble into a tightly packed single layer.

The material is still in development, and subject to potential barriers, but Mr Mayes says he expects his company's technology will surpass conventional hard disk density by the end of 2003.