#dna decoding

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UW researcher used the nanopore Mycobacterium smegmatis porin A (MspA). This bacterial pore has been genetically altered so that the narrowest part of the channel has a diameter of about a nanometer, or 1 billionth of a meter. This is large enough for a single strand of DNA to pass through. The modified nanopore is then inserted into a membrane separating two salt solutions to create a channel connecting the two solutions.   To read a sequence of DNA with this system, a small voltage is applied across the membrane to make the ions of the salt solution flow through the nanopore. The ion flow creates a measurable current. If a strand of DNA is added to the solution on one side of the membrane and then enters a pore, the bulky DNA molecules will impede the flow of the much smaller ion and thereby alter the current. How much the current changes depends on which nucleotides -- the individual molecules adenine, guanine, cytosine and thymine that make up the DNA chain -- are inside the pore. Detecting changes in current can reveal which nucleotides are passing through the nanopore’s channel at any given instant.  

What can you learn about a person in a day? You can note their eye color and height, find out whether they have siblings, and perhaps what they like to do in their free time. But how about learning that a person is genetically predisposed to developing colon cancer, or is likely to never go bald? [READ MORE]