Just wanted to point out: DNA isn't "organic". At least not in the normal sense. DNA is a code, a sequence containing every shred of information about a person. It can be interpreted in letters, numbers, or symbols just like any computer code. It can be digitized and measured in bytes and megabytes, just like a word doc on your computer. It can also be used the other way around, to store a bunch of data.
More info here: http://www.extremete...o-a-single-gram
It's been said in the games and books that Cortana was created from Halsey's DNA, and this is likely how it was done. By sequencing Halsey's DNA code, digitizing it, and using it to program Cortana in Halsey's image (both physically and mentally).