Posts tagged DNA

The MinION costs $1,000 and is the size of a candy bar. It connects to a laptop computer’s USB port. To have it read a DNA sample, you use a micropipette to drop a “DNA library” (more on that in a minute) through a millimeter-sized opening on the MinION. Inside the device are nanopores, cones just over a billionth of a meter wide, placed in a membrane. A steady ion current flows through these nanopores. Since each nucleotide (A, T, C or G) has a unique molecular makeup, each one is shaped a little differently. The unique shape passing through the pore interrupts the ion current in a specific way. Just as we can infer a shape by analyzing its shadow on a wall, we can infer a nucleotide’s identity from the disturbances it causes to the ion current. This is how the device converts bases to bits that stream into a computer.

via https://medium.com/neodotlife/nanopore–6443c81d76d3?source=ifttt————–1

But the well-publicized success stories obscure the fact that familial DNA searches can generate more noise than signal. “Anyone who knows the science understands that there’s a high rate of false positives,” says Erin Murphy, a New York University law professor and the author of Inside the Cell: The Dark Side of Forensic DNA. The searches, after all, look for DNA profiles that are similar to the perpetrator’s but by no means identical, a scattershot approach that yields many fruitless leads, and for limited benefit. In the United Kingdom, a 2014 study found that just 17 percent of familial DNA searches “resulted in the identification of a relative of the true offender.”

via http://www.wired.com/2015/10/familial-dna-evidence-turns-innocent-people-into-crime-suspects/