In it, a group of researchers led by Sarah Staniland at the University of Leeds, in Britain, describe using naturally occurring proteins to make arrays of tiny magnets,
similar to those employed to store information in disk drives.
The researchers took their __________ from Magnetospirillum magneticum, a bacterium that is sensitive to the Earths magnetic field thanks to the presence within its cells of flecks of magnetite, a form of iron oxide.
Previous work has isolated the protein that makes these miniature compasses. Using genetic engineering, the team managed to persuade a different bacteriumEscherichia coli, a ubiquitous critter that is a workhorse of biotechnologyto __________ this protein in bulk.
Next, they imprinted a block of gold with a microscopic chessboard pattern of chemicals.
Half the squares contained anchoring points for the protein.
The other half were left untreated as controls.
They then dipped the gold into a solution containing the protein, allowing it to bind to the treated squares, and dunked the whole lot into a heated __________ of iron salts.
After that, they examined the results with an electron microscope.
Sure enough, groups of magnetite grains had materialised on the treated squares, shepherded into place by the bacterial protein.
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