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DNA Identification. Where does DNA come from? 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. Cell. Where can DNA be found?. Cell Types. Blood. Hair Roots. Saliva. SAME.
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DNA Identification • Where does DNA come from? • 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
Cell Where can DNA be found? Cell Types Blood Hair Roots Saliva SAME Sweat 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
Nucleus Where is DNA in the body? Cell
Where types of DNA are found in a cell? Cell Mitochondrial DNA Nuclear DNA
Nucleus Paternal Chromosome Maternal Chromosome Where is DNA in the body?
Chromosome DNA Where is DNA in the body?
Double Helix A T C G DNA- What it looks like Units A =Adenine T =Thymine G =Guanine C =Cytosine
4 5 TCTA AGAT TCTA AGAT TCTA TCTA AGAT TCTA AGAT 7 6 AGAT TCTA AGAT TCTA AGAT TCTA TCTA AGAT TCTA TCTA AGAT STR Short Tandem Repeat AGAT DNA Profile =4,6 TCTA DNA Profile =5,7
Isolation of DNA Chemical DNA Blood Hair Roots Saliva Sweat Tissue
Epithelial DNA Semen stain Different Chemical Sperm DNA Chemical Differential Isolation of DNA Semen stain Remove Epithelial DNA Sperm DNA
DNA Amplification (making copies) Solution
DENATURE A A T T G C G C A A T T T A T A A T A T G G C C Heat Step one of a single cycle
ANNEAL A A G T G A T T C A C A A T T T T T C Step two of a single cycle
T G G A C A T T G A G T A A G T G A A T G A T A T A T T C T A T C C T EXTEND Step three of a single cycle
Amplification 28 Cycles 1 Cycle 2 Cycles DNA 3 Cycles 4 Cycles 5 Cycles PCR (Polymerase Chain Reaction)
Amplified DNA Analysis of amplified DNA DNA Profile
Area 5 Area 4 Area 3 Area 2 Evidence AREAS OF DNA Area 1 Sex Area 6 Ref.Std.2 Ref.Std.1 SAMPLE 14,15 14,15 17,18 17,18 23,24 23,24 X,X X,X 13,13 13,13 30,30 30,30 15,19 15,19 15,16 16,17 20,23 X,Y 12,14 30,30 13.2,15 15,16 16,17 20,23 X,Y 12,14 30,30 13.2,15
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.