This is going to sound really futuristic and awesome, but it isn’t. It’s actually being done right now, the idea of growing DNA.
Say, I kidnap someone. And me, being a stupid criminal, sends the family a ransom note and I lick the envelope. They can take that envelope, find just one little cell off of that envelope and use it to find me through the DNA.
Now, in reality, they cannot take that one single cell and analyze the DNA to find me. They need more than one cell, because, really, DNA is small.
So what scientists can do is toss the cell (maybe the DNA. I’m not sure now.) in a test tube, toss in the building blocks of DNA–the sugar and phosphates (backbones of DNA), and the adenine, cytosine, guanine and thymine–and toss in a DNA polymase so it can separate the DNA and let it sit for a day or so.
Once all this sits for a bit, we’ll have a lot of DNA that we can then analyze and find the kidnapper.
Now this can technically be used for a lot of other things that requires more than one cell of DNA. I just heard this in class and kept thinking to myself: Now, how can I use this in a story?
AS a note, this is called PCR.