DNA ID Flashcards
What is DNA?
the fundamental component of an organism, it holds the key genetic information required for an organism to function and is passed on to offspring.
What can DNA be used for?
Linking a suspect to a scene or identifying a species
What must be done first in the process of DNA analysis?
A sample must be obtained from the scene or the animal to be identified.
What are the disadvantages of old school DNA methods?
The usually require lots of material - not possible from crime scenes.
What are the advantages of old school methods of DNA analysis?
They are fast and cheap
What is the advantage of RAPD?
It is generated in PCR so lots of DNA can be produced.
What is the disadvantage of RAPD?
It is entirely random so a database cannot be created.
What does PCR form the basis of?
Many forensic DNA assays such as STR profiling and mtDNA sequencing.
Why is Taq polymerase used in extension?
It is found in hot springs so can withstand high temperatures.
What is the greatest advantage of PCR?
The speed at which it can be carried out.
What happens once PCR has been completed?
The DNA is run through electrophoresis and the bands can be compared to reference sequences of animals or suspects.
What are the disadvantages of PCR?
Degradation –> Low copy number of template = one allele not detected so individual falsely identified as homozygote. (Li, R. 2008)
What has been developed to combat the problems of degraded DNA?
DNAboost
What is the advantage of SNPs?
If the SNP is present in the sample, it’s likely the individual can be linked to the scene.
