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Old 05-15-2013, 10:53 AM   #16
briandc
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Location: Italy

Join Date: May 2013
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Quote:
Originally Posted by stefanoberri View Post
"In theory" it could be possible, but there are many serious obstacles to overcome.

At the moment "reading" the genetic code of a cell is disruptive. You need to process the DNA in such a way that you can't "put it back" into a cell. Even if you could, it is unlikely you can read the whole DNA of a cell without upsetting that cell.

Even if you could, it would be disruptive to read all DNA in all cells without damaging surrounding tissues/organs. How do you get to every liver cell without damaging the liver? You would need microscopic machines that run with no energy and automatically find EVERY cell and sequence their DNA. Today, such machines are the size of a large printer at best.

Even if you could, there are about 10^13 cells in an adult human being. Each has 6*10^9 nucleotides to be read (if you make a ASCII file with that sequence, each cell would require a 6GB file). Even if you had 1000 of such microscopic machines, each reading the DNA of each cell in one second, it would take about 317 years to finish. Furthermore, today, the sequencing costs approx 5000$ per genome and takes at best a couple of days each. You do the math.

Even if you could, it is not quite uderstood what makes a cell a cancer cell. Not for most cancers. If you give scientists the sequence of any of your cells, it is unlikely that they will be sure that that particular cell does not have a cancer mutation. What scientists can tell you, is to spot some well defined cancer sequences (search for EGFR, BRAF, KRAS, TP53). This is, of the above, the easiest bit, I would say, but still very very hard.

Computers are amazing and I love Linux, but I doubt this will be the approach.
But is there absolutely no other way to recognize a cancer cell without touching the DNA?

If a cancer cell can be recognized for other cancer-specific characteristics, such as color, size, density, whatever... then that's what the computer must be programmed to look for. As far as I see..


Brian
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