Organic Cotton Swabs

On the telly, they always collect blood samples and whatnot w/ Q-Tips. I know it's not real, but I'd imagine that;s how they do it in real life, too.

Why doesn't the DNA from the cotton plant contaminate the blood tests, since all living things contain DNA? I'd think you'd always have cotton residues when you test, and the machines could confuse the chemicals from the cotton with the chemicals from the actual blood?

Thanks!

DNA samples are processed by PCR (Polymerase Chain Reaction). To make this reaction occur primers are added. These are short complementary sequences of DNA that attach to specific sequences of DNA that are the target of the investigator. In Forensic cases, they use human specific primers, so theoretically you could contaminate the sample with DNA from any source but only the human DNA will be amplified. Since there is very little homology between humans and cotton, using cotton swabs would not be a problem.

2007-04-06 15:27:50 by sisofphil

138 prepared dc-motors, cotton balls, cardboard boxes 40x40x40cm Zimoun 2011 Installation view: Lydgalleriet, Bergen, Norway. Curated by Jørgen ...