Richard Jobin, PhD, is a forensic DNA specialist working in the Alberta government's Fish and Wildlife Enforcement division.
"I do forensic case work, a lot of which is with animals. I do work with human DNA, helping out police agencies or the coroner. Working with human and animal DNA involves almost identical tests and equipment, except that the chemical cocktail is different for different species. Actually, doing human DNA is easier, because there are commercially available kits and enormous pre-existing databases. For animals, we had to create our own test, set up and run our own databases, do our own statistics, that sort of thing."
Forensic DNA testing has come a long way in the past 20 years. DNA has been used as evidence since the mid-eighties, but the technology behind it has changed significantly. The old way of analyzing DNA, restriction fragment length polymorphisms or RFLP, involved chopping up bits of DNA, and comparing the resulting fragment lengths. The technology currently in use is polymerase chain reaction or PCR, which takes a small DNA sample as a template, and makes billions of copies. PCR also compares the length of DNA fragments, but because it makes copies of the DNA sample, you don't need nearly as much of it to get the same results. "Before, you may have needed 50 nanograms or a microgram of DNA. Now, you're down to less than one nanogram of DNA."
"With this new technique, you can get DNA evidence from crime scenes 40 to 50 years old," says Jobin, "if you keep a sample dry or frozen, the DNA can last, intact, for thousands of years." Good news for cold case investigators!