Class Notes (1,100,000)
CA (620,000)
Western (60,000)
ANTH (900)
Lecture

Lecture 21 – Disadvantages of mtDNA


Department
Anthropology
Course Code
ANTH 2235A/B
Professor
Eldon Molto

This preview shows half of the first page. to view the full 1 pages of the document.
Lecture 21 Disadvantages of mtDNA
The high copy number and the sensitivity of PCR makes it more susceptible
to contamination (must have clean lab facility for mtDNA analysis (=very
costly to construct lab and to pay for case (~$1500-2000 American)
Can’t discriminate maternal relatives, in small areas with high degree of
endogamy this could be problematic
Low probative value (usually 1/100 to 1/1000) depending on size of
database
New to courts (voir dire in Canada 1999) = more acrimony and less
acceptance
Possibility of heteroplasmy (two profiles at a locus in one individual)
Difficult to quantify
Contamination Control
o Protective clothing is worn in the field when possible and only a
designated person collects samples
o All field and lab personnel should have their profile on record
o MtDNA is more prone to contamination from extraneous sources
because of:
1. High copy number in conjunction with
2. PCR selectivity
o Main concern in the in R. v. Murrin voir dire trial
o In order to understand how a lab is structured to control for
contamination the whole process requires review
Controls for mtDNA Analysis
o Bacteria or fungiprimer design (a primer or oligonucleotide is
species specific if large enough!)
o All personnel in the field and lab should have their DNA profiles on
file to rule them out as a potential source of contamination
o Clean Lab where special controls of evidentiary samples are
carried out including separate areas for evidentiary and exemplar
samples
Contamination Controls: Lab
o Lab design separate areas for processing exemplar and
comparison samples
o Clean room with positive air flow
o Stringent procedural controls to prevent modern contamination
o Negative controls in electrophoresis runs
o Careful laboratory practices: Experiments carried out in a clean
lab facility
o Protective clothing
o Sterilization of equipment and reagents
You're Reading a Preview

Unlock to view full version