Revision PPQs Flashcards
How do you determine the presence of a particular gene?
PCR
How do you determine whether a particular gene is expressed?
RNA sequencing
How do you determine which genes are expressed?
PCR
RNA sequencing
How do you work out if a particular gene is required for a particular process?
GWAS
CRISPR
A newly discovered virus, LEOBA, is known to infect leukocytes. You want to design a strategy to diagnose infection using blood samples.
Which method would be most suitable?
PCR
A newly discovered virus, LEOBA, is known to infect leukocytes. You want to design a strategy to determine the viral load (titre) of infected patients.
Which method would be most suitable?
qPCR
You hypothesise that the virus supresses the expression of several genes in target cells, leading to an decreased inflammatory response.
Which method would be most suitable to identify which genes are supressed?
RNA seq
You hypothesise that the virus supresses the expression of several genes in target cells, leading to an decreased inflammatory response.
List the steps you would take to perform an RNA seq analysis of infected cells? (4
1) Take leukocytes from infected and uninfected volunteers
2) Purify mRNA
3) Convert to cDNA (using reverse transcriptase)
4) Sequence (quantify) using next generation sequencing
5) Determine statistical significance of differences for each gene
You hypothesise that the virus binds a specific protein on the surface of target leukocytes to infect cells.
How would you determine whether this protein was required for viral infection of cultured leukocytes? (3)
Take some leukocytes
Knock-out / disrupt the gene coding for the protein (using CRISPR or RNAi)
Expose cells to virus in culture
Compare levels of viral DNA in knock-down cells compared to WT (using PCR/qPCR)
Your results are inconclusive and the viral mechanism of entry remains unclear.
However, you still want to tray and make an effective therapy! You have a compound library and want to identify compounds that inhibit viral entry.
Which method might you use to do this?
screen
You want to know whether the virus is sexually transmitted? You interview two groups of people – one with the virus and one without - to determine their sexual habits.
What kind of study design is this? Case study Case-control Cohort GWAS Randomised control trial
case-control
Name a potential confounding variable that would be important to account for in your study design.
DRUGS
How might you perform a cohort study to address the question? (3)
Take a group of volunteers from the target population
Ask them to record their sexual activity over a period of time
Determine whether there is a higher incidence of LEOBA in those who have unprotected sex.
