If, like me, you’ve done any molecular cloning, then you’ve probably spent hours loading the wells of agarose gels with samples and waiting for the gels to run before taking photographs of them.
That may soon be a thing of the past, thanks to a new technique for the seperation of macromolecules developed by researchers at MIT. The team, led by Jongyoon Hang, a professor of Electrical Engineering and Biological Engineering, has microfabricated a small microchip containing millions of uniformly-sized fluidic nanofilters.
The ‘molecular sieve’ can be used for size-fractionation of proteins, polysaccharides and double-stranded DNA. Because the size of the filters is precisely controlled, the sieve can fractionate macromolecules more efficiently than electrophoresis. It can also be used to screen proteins by size and shape.
The sieving process is based on a theory called the Ogsten sieving mechanism, according to which, pores of varying size act as energy barriers to molecules, so that smaller molecules pass through the filters more quickly than larger ones.
“This is the first time anyone was able to…confirm this theor[y]” Han said. “With our nanopore system, we control the pore size…[and] the sieving process of the protein molecules. We can change the pore shape and engineer a better separation system.”