Genetic techniques and applications Flashcards
What is PCR
In vitro synthesis of large amounts of DNA by copying from small quantities
what defines the small boundaries of synthesis in PCR?
Oligonucleotides
What is the role of DNA polymerase?
To synthesis DNA from the monomers
what is the first step of PCR?
Heat denaturation - Heat the DNA at 94 degrees, the hydrogen bonds break
What is the second step of PCR?
Primer annealing at 55 degrees, then primer extension at 72 degrees
- deoxribonucleotide being added by polymerase
What happens to the PCR products?
they are separated by gel electrophoresis stained DNA by UV light.
What is PCR used for?
to determine the presence or absence of a product
to determine product size by gel electrophoresis
Which region is difficult to PCR
GC-rich regions are difficult to PCR
What is fragile X syndrome?
Fragile X syndrome is associated with the expansion of the CGG trinucleotide repeat affecting the Fragile X mental retardation 1 (FMR1) gene on the X chromosome, resulting in a failure to express the fragile X mental retardation protein (FMRP), which is required for normal neural development
What is chain termination in PCR?
New strands are synthesised all different lengths each ending in ddTTP
this happens overtime a dATP occurs in the original template fragment
