NOV 10, 2016 2:46 PM PST

Why DNA Evidence isn

WRITTEN BY: Xuan Pham

Hollywood TV crime shows are notorious for oversimplifying the arduous, complicated tasks of real DNA investigation. In such shows, DNA can always be recovered, no matter how small, aged, degraded, or contaminated the sample may be. A faint smidgen of a blood spot found on a decomposed rag that's been sitting in a compost heap for the past 31 years? No problem, the forensic analyst will have the DNA fully extracted (on the first try) and cross-checked to any database within 24 hours.

In reality, DNA extraction can often be very tricky, especially when samples are limited in quantity, old, contaminated, or otherwise degraded. DNA is a biological molecule that's resilient, but by no means indestructible. It is susceptible to all forms of breakages, mutations, and deterioration, which all complicate the extraction process immensely. The difficulty compounds in trying to sequence DNA that isn't whole or pure. This can yield fragmented DNA sequences, which when not entirely unique, can make it difficult to match in a database. In addition, contaminated samples can obscure the DNA profile, which would increase the signal to noise ratio and complicate matching.

The power of DNA fingerprinting is unquestionable. Indeed it's a tool widely used to not only convict criminals, but also to exclude and exonerate innocent people. However invaluable, DNA testing is not a simple cakewalk as Hollywood labs make it seem. Watch the video to learn more!
About the Author
  • I am a human geneticist, passionate about telling stories to make science more engaging and approachable. Find more of my writing at the Hopkins BioMedical Odyssey blog and at TheGeneTwist.com.
You May Also Like
APR 16, 2020
Earth & The Environment
APR 16, 2020
NASA Illustrates the Complexities of Atmospheric Chemistry
What do scientists see when looking at Earth’s atmosphere? Well, it’s complicated, especially the chemistry ...
APR 16, 2020
Earth & The Environment
APR 16, 2020
Scientists Discover Evidence of Ancient Rainforest in Antarctica
Back in 2017, Dr. Johann Klages and his team were going about their usual business of drilling into the seafloor to extr ...
APR 22, 2020
Chemistry & Physics
APR 22, 2020
Want to Peek at Atoms? There's a Microscope for That
Optical microscopes can help us see the microscopic world, but to use them to examine individual atoms is like measuring ...
APR 28, 2020
Space & Astronomy
APR 28, 2020
NASA's Swift Telescope Measured the Water Loss of This Interstellar Comet
When the interstellar comet 2l/Borisov made its first appearance in our solar system, astronomers were quick to turn the ...
MAY 03, 2020
Space & Astronomy
MAY 03, 2020
These Contractors Will Develop Lunar Landers for NASA's Artemis Mission
NASA seems to be moving quickly to get the ball rolling for its lunar-centric initiative dubbed Artemis. The program aim ...
MAY 24, 2020
Space & Astronomy
MAY 24, 2020
Here's Why SpaceX is Using Heavy Stainless Steel to Make Starship
SpaceX is perhaps best known for its reusable Falcon 9 rocket, the same variety that will be lofting astronauts into out ...
Loading Comments...