Human Identity Testing

1
Human Identity Testing
Purpose Match a person to a DNA sample.
Examples

• Paternity Test
• Genetic History
• Historical (Thomas Jefferson, Sally Hemings)
• Genealogical
• Forensic
• Missing Persons
• Identifying body parts

2
Forensic DNA
Source Any biological material containing cells
Examples

• Blood
• Hair (must have root)
• Bone / teeth
• Saliva
• Urine
• Semen
• Vaginal secretions
• Futuristic discarded epidermal cells

3
CODIS(Combined DNA Index System)
Purpose Allow participating laboratories to
exchangeand compare profiles at a national level
in electronic form.
Factoids

• 1990 pilot launched by FBI
• 1994 DNA Identification Act passed
  (authorized FBI to implement a national
  forensic data base)
• 1998 became operational
• 2000 added missing persons

4
CODIS 13 STR Loci and AMEL
5
STR(Short Tandem Repeat)
TH01 TCAT repeat in the first intron of
the tyrosine hydroxylase gene
6
STR Allele Frequencies
45
40
TH01 Marker
35
30
Caucasians (N427)
25
Blacks (N414)
20
Hispanics (N414)
15
10
Proc. Int. Sym. Hum. ID (Promega) 1997, p. 34
5
0
6
7
8
9
9.3
10
7
Genotyping at the TH01 Locus
Moe 7/9
Larry 9.3/9.3
Curly 6/9
Reference
10
6
7
8
9
9.3
8
Moe 7/9
Larry 9.3/9.3
Curly 6/9
CrimeScene DNA
9
AMEL(amelogenin locus)

• quick, inexpensive sex determination
• AMEL gene on X chromosome has 6 fewer
  base pairs than the gene on the Y chromosome
• XX give one short peak
• XY give two peaks, one short and one long

10
firstperson
secondperson