Biomedical Engineering Reference
In-Depth Information
9.14 Conclusion
In the miniaturization trend of biotechnological microsystems, microflows are often
not selective or specific enough to correctly perform their expected role of carrier.
Functional magnetic microbeads are then used as additional carriers, bringing the
required selectivity. This is why magnetic beads have been found to be a very pow-
erful complementary tool for manipulating biological objects and they appear now
to be one of the most useful tools in biotechnology.
Magnetic beads can bind to many different target molecules by the principle of
functionalization and they can unbind by elution, so they can be used as temporary
carriers. The applied force on magnetic beads can be precisely controlled by the ac-
tion of an external magnetic field, leading to a simplified design of the microsystem.
Moreover, with the combination of magnetism and fluorescence, beads are easily
tracked and detected under the microscope.
Magnetic beads can be assembled to form new biotechnological tools such as
magnetic chains, magnetic fluids, and magnetic membranes. Magnetic chains can
be arranged to form sieving matrices to separate long DNA strands, magnetic fluids
are used primarily to perform micropumping, and magnetic membranes are well
suited to enhance mixing in microsystems.
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