Friday, November 16, 2018

Mosquitoes In Forensic Science

Forensics is still a new science that combines science and criminal justice and can provide evidence in a crime scene to either convict criminals or prove their innocence. There has been an emergence of new techniques in how exactly we extract DNA. Forensic scientists often extract DNA from physical objects within the crime scene. Other methods include locating DNA samples on domestic animals such as dogs and cats.

This article focuses on forensic entomology. A team of forensic scientists are discovering the possibilities of using DNA of human blood taken from the stomach of mosquitoes to solve criminal cases. Mosquitoes have been used to confirm the presence of a person in the crime scene although its reliability has been questioned. The article I read focused on one question: how long would the DNA remain viable as it becomes digested in the mosquito’s stomach? Volunteers of this study were asked to let mosquitoes bite them. After allowing a certain time for digestion, the DNA was extracted and amplified using polymerase chain reaction, or PCR techniques. This was used to determine the quantity of DNA left right after the mosquito’s blood feeding and who exactly the DNA came from. After two days of using PCR, the DNA was still identifiable but after the third day, the DNA was completely digested and therefore unrecognizable.

I think this form of DNA extraction is disregarded by some forensic scientists especially given that it is not the most reliable source. The fact that mosquitoes are only prevalent during the summer season and the chances of the criminal getting bit show that there are slim chances that the mosquito’s stomach contains the correct matching DNA or even any DNA. Also in the case where there are many mosquitoes at the crime scene, the work to amplify all the DNA from the mosquitoes can become burdensome and may result in zero evidence. But in the case where there is no evidence to begin with, then I think it’s a feasible beginning.


1 comment:

  1. Excellent article! I agree that using a mosquito is unreliable for forensic evidence because of how uncontrollable they are in the wild but it is amazing that human blood stays recognizable in a mosquitos stomach up to two days later! I feel like this can be used for something useful but not sure if it will hold up in the court room.