DNA Profiling - STR biology and artifacts

1. DNA Profiling

2. Short Tandem Repeats (STR)
The selection of specific loci
• The loci have a
high discriminating power.
•The loci are stable in evidence
samples.
•There is a consensus panel of
core loci for use in DNA
databases.

5. Scientific Working
Group for DNA
Analysis Methods
(SWGDAM)
Y-STR loci:
•DYS19
•DYS385 A/B
•DYS389I
•DYS389II
•DYS390
•DYS391
•DYS392
•DYS393
•DYS438
•DYS439
•DYS19

6. Factors in deciding the loci included in multiplex PCR:
•Locus size and overlap
•Number of alleles
•Thermal cycling parameters
•Primers
•Dyes

8. AmpFℓSTR (Applied Biosystems)

18. https://strbase-archive.nist.gov/index.htm

32. Comments
on Sample
Preparation

34. Repeat: [CA]n
Repeat: [AGAGAT]n[AGAGAT]m

35. Repeat: [TATC]
Repeat: [TCTA], [TCTG] Repeat: [GAAA]

36. DNA strand mispairing

45. https://strbase-archive.nist.gov/tri_tab.htm

53. https://strbase-archive.nist.gov/mutation.htm

64. Pull-up of peaks in one
color may be due to very
high peaks in another
color.
Pull-up is a spectral
artifact that is caused by
the inability of the
software to compensate
for the spectral overlap
between the different
colors if the peak height is
too high.

74. This Photo by Unknown Author is licensed under CC BY-SA