Transcript Document

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
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
CODIS
(Combined DNA Index System)
Purpose: Allow participating laboratories to exchange
and 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
CODIS: 13 STR Loci and AMEL
TPOX
D3S1358
D8S1179
D5S818
FGA
CSF1PO
TH01
VWA
D7S820
AMEL
D13S317
D16S539
D18S51
D21S11
AMEL
STR
(Short Tandem Repeat)
TH01: TCAT repeat in the first intron of the
tyrosine hydroxylase gene
TCATTCATTCATTCATTCATTCAT
1
2
3
4
5
6
TCATTCATTCATTCATTCATTCATTCAT
1
2
3
4
5
6
7
TCATTCATTCATTCATTCATTCATTCATTCAT
1
2
3
4
5
6
7
8
STR Allele Frequencies
45
40
TH01 Marker
Frequency
35
30
Caucasians (N=427)
Blacks (N=414)
Hispanics (N=414)
25
20
15
10
*Proc. Int. Sym. Hum. ID
5
(Promega) 1997, p. 34
0
6
7
8
9
9.3
Number of repeats
10
Genotyping at the TH01 Locus:
Moe: 7/9
1 2 0
1 2 4
1 2 8
1 3 2
L engt h
1 3 6
1 4 0
1 4 4
1 3 6
1 4 0
1 4 4
1 3 6
1 4 0
1 4 4
(bp)
Larry: 9.3/9.3
1 2 0
1 2 4
1 2 8
1 3 2
L e ngt h
(bp)
Curly: 6/9
1 2 0
1 2 4
1 2 8
1 3 2
L engt h
(bp)
Reference
10
6
120
124
7
128
8
132
Lengt h (bp)
9
136
9.3
140
144
Moe: 7/9
1 2 0
1 2 4
1 2 8
1 3 2
L engt h
1 3 6
1 4 0
1 4 4
1 3 6
1 4 0
1 4 4
1 3 6
1 4 0
1 4 4
136
140
144
(bp)
Larry: 9.3/9.3
1 2 0
1 2 4
1 2 8
1 3 2
L e ngt h
(bp)
Curly: 6/9
1 2 0
1 2 4
1 2 8
1 3 2
L engt h
(bp)
Crime
Scene
DNA
120
124
128
132
Lengt h (bp)
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”
Human Identity Testing with Multiplex STRs
AmpFlSTR® SGM Plus™ kit
amelogenin
D19
D3
D8 TH01
VWA D21
D16
D18
D2
FGA
first
person
amelogenin D3
D19
second
person
D8
VWA
TH01
D16
D21
FGA
D18
Simultaneous Analysis of 10 STRs and Gender ID
D2