Profiling systems

Question 1

profiling system time line

Answer 1

1985 MLP
1990 SLP
1994 STR-Quad
1995 SGM
1999 SGM+
2014 DNA 17

all with increasing discrimination

Question 2

MLP (multi locus probe)

Answer 2

large sample needed, lengthy, complex results

Question 3

SLP (single locus probe)

Answer 3

easy to interpret, results in days
not sensitive, bad for mixtures

Question 4

SGM (second generation multiplex)

Answer 4

still pre database, needed 6 loci plus sex test

Question 5

SGM+ (second generation multiplex plus)

Answer 5

database in 1995
needed 10 loci plus sex test

Question 6

DNA 17

Answer 6

tiny amounts needed, pico gram LoD, higher sensitivity
can be used across countries databases

DNA 21 in scotland

Question 7

criteria for a good profiling system:

Answer 7

1. discriminating power
2. sensitivity
3. Ability to deal w/ artefacts
4. speed
5. ability to deal with mixtures
6. ability to conduct database searches

Question 8

Electropherogram (EPG)

Answer 8

is the read out of a profile
homozygous peak = one peak representing 2 alleles
left –> right = smaller –> larger fragments
peak height proportional to amount DNA

Question 9

potential reasons for non concordance between systems

Answer 9

• data entry error
• mutation - retest using other multi plex