D.N.A.

Duration: 15 Minutes

'DeoxyriboNucleic Acid' - known as D.N.A

We explain about the national D.N.A. database introduced at the end 2015. We show how samples are taken from suspects/witnesses and we give a practical demonstration to show how D.N.A. is recovered from crime scenes.

We give the students details of high profile cases where D.N.A. has been used and how advancements in this area of science has proved beneficial in some cold cases.

The human body is composed of billions of cells of many different types i.e. blood cells, hair, skin, bone, muscle cells, heart, lung, spleen. Almost all cells contain a nucleus (except the red blood cell) and within the nucleus of each cell is an identical copy of a person’s DNA. Because of this DNA from a person’s blood will be the same as that found in their saliva or hair roots.

Half of our DNA is inherited from our mother and half from our father. Except for identical twins, each person’s DNA is unique. In fact, the chances of two people having the same profile within the Irish population is one in a thousand million.

[source: Forensic Science Ireland (http://www.forensicscience.ie/dna)]