Any biological material can be used: blood, saliva, bone, urine, feces, hair, teeth, tissue, sperm, semen, and even cells.
These biological materials could be contained in any item that could have been touched or worn by the suspect, these items could be masks, gloves, clothes... and even simple things like cigarettes and toothpicks ...
Someone is a ''critical'' suspect when its DNA into where it is not supposed to be.
For example, investigators picked up a small hair clip which the victims confirm was not theirs. Several hairs were recovered which can be used to obtain a DNA profile of the suspect.
Then, these pieces of evidence can be passed to the forensic scientists. Most DNA samples submitted undergo the following process:
1-Extraction
Extraction is the process of freeing the DNA from the cell.
2-Quantitation
Quantitation means 'concluding' how much DNA you have.
3-Amplification
Amplification is where scientists produce several copies of the DNA to characterize it.
4-Separation
Separation is the process of separating amplified DNA to allow subsequent identification.
5-Interpretation
It's the process where they would compare obtained DNA profiles to known ones.
6-Assurance
This is where 'higher rank' (In serval countries) scientists will be reviewing analyst reports for technical accuracy.
For the sake of brevity, I didn't get into details but I will be writing an article soon about how each one of these steps is done!
This DNA analysis process provides a chart called an electropherogram, which shows the genetic material present at each locus tested.
Finally, they match the profile obtained previously against a large, national database!
Sources:
Picture Credit:
All Taken from © pixabay.com & Wikipedia
One more thing, Do you want to support "science" articles on Steemit? Join the #steemSTEM channel
If you like this post , Please do not forget to upvote and follow me
