Biological Samples and DNA Flashcards
Which cases involve biological samples?
Assaults Road traffic accidents Murder/suicide Industrial accidents Major disasters
Are biological samples limited?
yes
who sometimes collect biological samples meaning FS have no choice?
pathologists
what makes a sample admirable in court?
Had to be a correct sampling technique used and good storage
When doe chain of custody begin?
before the sample is taken
When must the Human Tissue Act 2004?
If tissue is taken from a individual there must be permission and it must be stored/disposed of properly. For a living individual - invasiveness of sample collection should be considered.
When can biological samples be taken?
antemortem (living)
peri-mortem ( time of death)
post mortar (after death)
Who developed the ABO system and when?
Landsteiner in 1901
what produce antibodies and why?
lymphocytes when a foreign substance is in the body
what antigen does blood group A have?
antien A
what antigen does blood group B have?
antigen B
what antigens do blood group O have?
none
what antigens do blood group AB have?
both A and B
When was the rhesus system developed and by who?
1930 by Landsteiner and Weiner
the rhesus monkey antigen is presents tin how many humans?
85%
who developed DNA fingerprinting and when?
Dr Alec Jeffreys in 1984
what is dNA made from?
Deoxyribose sugar, phosphate backbone and nucleotides
what are the four nucleotides?
adenine, thymine, guanine, cytosine,
how many hydrogen bonds does AT have?
2
how many hydrogen bonds does CG have?
3
How many chromosomes does a person have?
46 or 23 pairs
Where can DNA be found?
White blood cells Sperm cells Hair follicle cells Sweat Saliva Fingerprint residues
how is DNA extracted?
concentration of cellular material, purification, breaking-up cells, transfer DNA into solution.
How do you analyse DNA fragments?
gel electrophoresis
How many `DNA profiles does NDNAD contain?
5 million
what happens if you’re arrested ?
DNA is added to the system
which was the earliest method used?
blood typing
Why is DNA profiling better than Blood typing?
Ability to individualise the source
