PCR Flashcards
What is PCR?
Polymerase chain reaction
What does polymerase refer to?
It refers to a special type of DNA pol that works at high temperatures
At what temperature does your DNA pol function?
72ºC
What is a chain reaction?
A self=sustaining chemical reaction yielding products that cause further reactions of the same kind
What are the products in PCR?
The amplified target DNA referred to as copies.
So amplifying would be… doing that to the DNA
If you start with three copies in a PCR reaction, how many copies will there be in cycle 4?
Start: 3
Cycle 1: 6
Cycle 2: 12
Cycle 3: 24
Cycle 4: 48
What is the purpose of PCR?
To allow you to obtain a lot of copies of DNA sequences by amplifying the target DNA so that it can be further studied
What is a diagnostic laboratory?
A lab that screens blood for the presence of HIV.
Med techs are trying to amplify viral chromosomes that may be present in the blood
What do test results represent in diagnostic labs?
If there is PCR product, the test is positive
If there is no PCR product, the test is negative
How is DNA fingerprinting used in crime solving?
DNA in a blood, saliva, hair, or semen sample can be amplified so that it can be analyzed to determine if the suspect’s PCR profile matches what was found at the crime scene
What are polymorphisms?
Differences in DNA between individuals
Many of those involve tandom repeats
What are variable number tandom repeats (VNTR) loci?
Regions that show variation in the number of tandom repeats
Should all the VNTR’s match up between the PCR profile at the crime scene and the PCR profile of the suspect if the suspect did it?
Yes, they should all match
What can students inherit from their parents?
Two different alleles
Uhhhhhhh
What are the similarities between DNA replication and PCR?
In both processes, a primer is needed and the DNA strands need to be separated
What are the differences between DNA replication and PCR?
The entire chromosome is copied in DNA replication
Only a short segment is amplified in PCR
What kind of primers are used in DNA replication? How many?
Two or more RNA primers are used to copy DNA
What kind of primers are used in PCR? how many?
There are two DNA primers because both strands of the target DNA are copied and DNA pols need an existing strand of DNA to which nucleotides are added
Where do primers come from for PCR?
… ordered from a company
The primer remains as part of the product
Where do primers come form in DNA replication?
Primers are made in the cell
Removed during the process
Is helicase needed for PCR?
No
What is used to break H bonds in PCR?
Heat
