PCR, Mutagenesis, DNA and RNA-Seq Flashcards
What is the function of DNA hybridization?
identifies a specific DNA sequence within a DNA sample
How are DNA fragments cut? (Southern Blot Analysis)
cut with specific restriction endonucleases
How are different fragments separated? (Southern Blot Analysis)
separated by size with gel electrophoresis
How are DNA fragments denatured? (Southern Blot Analysis)
with an alkali to expose the bases and are transferred to a membrane
What happens to the DNA fragment after it is transferred to a membrane? (Southern Blot Analysis)
membrane is probed with a radioactively or otherwise labeled single stranded DNA molecule that is complementary to the target DNA
What is the function of the probe? (Southern Blot Analysis)
hybridizes with any DNA fragments containing the target sequence. These fragments can be identified by autoradiography, chemiluminescence, or fluorescence
What is the purpose of Northern Blot Analysis?
gene expression is most often controlled at the level of transcription so it is useful to examine RNA levels
How are RNAs separated? (Northern Blot Analysis)
separated by denaturing gel electrophoresis, transferred to a membrane for probing with a leveled DNA (or RNA) probe that is complementary to the RNA (gene) of interest
What is the function of hybridization of the probe to the RNA? (Northern Blot Analysis)
identifies transcript and reveals its size
What are the base requirements for DNA synthesis? (4)
- a single-stranded DNA template
- an annealed (complementary) primer with a 3’ OH
- all four dNTPs (dATP, dCTP, dGTP, dTTP)
- DNA polymerase
What is the function of DNA Polymerase?
catalyzes DNA synthesis by activating 3’ OH
What is nucleophilic displacement?
involves the movement of an electron from an electron-rich atom (nucleophile) to an electron-poor atom (electrophile)
When is nucleophile attacked encouraged?
when a proton is removed by a general base on an enzyme – here the H+ on the 3’ OH is removed
What do enzymes like DNA Polymerase provide?
groups that act as acids or bases and encourage proton movements – acid-base catalysis
What is the function of PCR?
amplification of large amounts of a specific or random DNA from a small sample for various purposes
What are the purposes of PCR? (7)
- cloning
- sequencing
- making probes
- gene mapping
- gene expression analysis
- mutagenesis
- diagnostics/forensics
What is the amplification from n cycles?
2^n, assumption: 100% of all templates in every cycle
What are the molecular requirements for PCR?
- template DNA
- primer pair complementary to DNA sequences that flank the region to be amplified, correctly oriented
- DNA Polymerase (thermostable)
- dNTPs