DNA analysis Flashcards
1
Q
where do we extract DNA from?
A
- blood
- body hair
- bones
-teeth - mucus
- saliva
- tissue cells
- semen
2
Q
how is DNA extracted and amplified?
A
via a process called Polymerase Chain Reaction
3
Q
why do we extract DNA?
A
- forensic science
- paternity testing
- family ancestry
- disease testing/ screening
- wildlife conservative
- archaeological findings
4
Q
How does DNA extraction take place?
A
- cells in the sample are broken open - by blending or grinding
- fats and proteins in the mixture are emulsified -adding detergent and salt
- ethanol is added and the sample is centrifuged to separate DNA from the rest of the cell debris
- extracted DNA can be amplified, sequenced and analysed
5
Q
What is the purpose of PCR?
A
used to amplify extracted DNA fragments
6
Q
what are the applications of PCR?
A
- gene isolation
- sequencing
- cloning
- mapping mutations
- studying gene expression
- diagnostic testing
7
Q
How does PCR work?
A
- temperature changes within the machine start DNA replication using primers
- fragments are doubled each cycle
8
Q
What tools are used in PCR?
A
- PCR machine
- DNA polymerase
- primers
- nucleotides
- sometimes fluorescent probes are used
9
Q
what do we need for PCR?
A
- water and buffer
- magnesium
- nucleotides
- primers
- DNA polymerase
- DNA Template
10
Q
What is taq polymerase?
A
- DNA polymerase builds new strands of DNA
- used with PCR
- originally isolated from Thermus aquaticus bacteria
very heat stable as naturally found in thermal hot springs - most active around 70°C
11
Q
What are the 3 PCR changes?
A
- denaturation
- annealing
- extension
12
Q
when does denaturation occur?
A
at 90°c
13
Q
when does annealing occur?
A
- primers bind to single-stranded DNA
- 55°c- 65°c
14
Q
when does extension occur?
A
- polymerase extends primers
- 72°C
15
Q
what is DNA profiling?
A
- where a specific DNA pattern called profile is obtained by bodily tissue
- determines individual DNA characteristics
