DNA Identification Where does DNA come from? What is it? 1/2 from mom 1/2 from dad What is it? “Blue print” of life How is DNA different among us? Common vs Different What does “DNA” mean? Deoxyribonucleic Acid

Where can DNA be found? SAME Cell Cell Types Blood Hair Roots Saliva Sweat What does DNA mean? DNA stands for deoxyribonucleic acid. This is just a big name for describing what DNA is made up from. Where can DNA be found? DNA is found in virtually all of our cells. Some examples of where cells are found are blood, hair roots, saliva, sweat, semen and various tissues. All the DNA from one individual will be the same no matter what cells are looked at. Thus, the DNA from blood will be the same as that from muscle. Semen Various Tissue

Types of objects where DNA may be found Blood Stains Semen Stains Chewing Gum Stamps & Envelopes Penile Swabs Sweaty Clothing Bone Hair Fingernail Scrapings Saliva Where does DNA come from? DNA comes from your mother and father. Half from each. This DNA comes from your parents in the form of a Chromosome. A chromosome is the way the DNA is packaged. Like you would place something in a box to keep it all together. The chromosome would be the box and the DNA would be inside the chromosome.

Where is DNA in the body? Cell Nucleus Where does DNA come from? DNA comes from your mother and father. Half from each. This DNA comes from your parents in the form of a Chromosome. A chromosome is the way the DNA is packaged. Like you would place something in a box to keep it all together. The chromosome would be the box and the DNA would be inside the chromosome.

Where types of DNA are found in a cell? Mitochondrial DNA Nuclear DNA

Where is DNA in the body? Nucleus Paternal Chromosome Maternal Where does DNA come from? DNA comes from your mother and father. Half from each. This DNA comes from your parents in the form of a Chromosome. A chromosome is the way the DNA is packaged. Like you would place something in a box to keep it all together. The chromosome would be the box and the DNA would be inside the chromosome. Maternal Chromosome Paternal Chromosome

Where is DNA in the body? Chromosome DNA Where does DNA come from? DNA comes from your mother and father. Half from each. This DNA comes from your parents in the form of a Chromosome. A chromosome is the way the DNA is packaged. Like you would place something in a box to keep it all together. The chromosome would be the box and the DNA would be inside the chromosome.

DNA- What it looks like Double Helix Units A =Adenine A T T =Thymine G C T =Thymine G =Guanine DNA: - double stranded molecule - made of four bases - Sugar phosphate backbone - blue print of life and is the same in all nucleated cells - combination of the bases that determines a persons genetic make up - everybody’s genetic make up is different except for identical twins - inherited 1/2 from mother and 1/2 from father C =Cytosine

STR 4 6 DNA Profile =4,6 5 7 DNA Profile =5,7 Short Tandem Repeat AGAT TCTA TCTA TCTA TCTA TCTA TCTA TCTA DNA Profile =5,7

Isolation of DNA Blood Hair Roots Saliva Sweat Tissue Chemical DNA The isolation process consists of taking part of the evidence say from a bloodstain or vaginal swab and placing it into a tube. I will then add some chemicals that will break open the cells and allow me to get the DNA. In the case of a vaginal swab sample I will continue to get the DNA from the sperm by adding a different chemical. Since sperm have a different outer coating I am able to separate the female cells from the male cells.

Differential Isolation of DNA Semen stain Epithelial DNA Sperm DNA Chemical Semen stain Different Chemical Remove Epithelial DNA Sperm DNA

Amplification (making copies) DNA Solution

DENATURE Step one of a single cycle G T A C Heat T G C A

ANNEAL Step two of a single cycle A T G T A C

EXTEND Step three of a single cycle C A G T A T G A T G A T A C

PCR (Polymerase Chain Reaction) Amplification PCR (Polymerase Chain Reaction) 5 Cycles 28 Cycles DNA 4 Cycles 3 Cycles 2 Cycles 1 Cycle The amplification or copy making of the DNA is what makes PCR so useful. I can start out with a small amount of DNA and after a bunch of cycles have a large amount of DNA.

Analysis of amplified DNA Profile

Evidence Area 1 Area 2 Area 3 Area 4 Area 5 AREAS OF DNA SAMPLE Sex Area 6 15,16 16,17 20,23 X,Y 12,14 30,30 13.2,15 Ref.Std.2 Ref.Std.1 15,16 16,17 20,23 12,14 30,30 X,Y 13.2,15 14,15 17,18 23,24 13,13 X,X 15,19 14,15 17,18 23,24 13,13 30,30 X,X 15,19

STR results The DNA from the evidence stain and the reference sample from the suspect match. The frequency of this matching pattern is approximately 1 in 520,000,000,000 in the Caucasian population, 1 in 618,500,000,000 in the African American population and 1 in 532,000,000,000 in the Hispanic population. Based on these results the suspect is the source of the evidence stain to a reasonable degree of scientific certainty.