Molecular Genetics Methods MCQs Flashcards
You are performing an experiment where you would like to analyse DNA molecules in the size range 500 kilobases-1megabase. Which type of procedure would be most suitable?
A. Standard agarose gel electrophoresis
B. Standard polyacrylamide gel electrophoresis
C. Pulse gel field electrophoresis
C. Pulse field electrophoresis.
Separates depending on size, and can operate above the kilobase range
During SSCP experiments, nucleotide substitutions, such as mutations in single stranded DNAs causes them to migrate at different rates because the nucleotide substitutions…
A. significantly alter the molecular weight of the ssDNA.
B. result in the ssDNA taking on a different shape.
B. They result in the ssDNA taking on a different shape.
You would like to investigate the suspected presence of a point mutation in a patient’s DNA sample and decide to start your investigation with an SSCP experiment. What electrophoresis conditions would you employ during the experiment?
A. Denaturing conditions
B. Non-denaturing conditions
B. Non-denaturing conditions.
Denaturing conditions would prevent the ssDNA from forming secondary structures which would reveal the presence of a point mutation.
During a size determination analysis, which two of the following are you most likely to add formamide to?
A. Single stranded DNA
B. Double stranded DNA
C. Single stranded RNA
D. Double stranded RNA
A. Single stranded DNA
C. Single stranded RNA
Formamide is used to denature single stranded nucleic acids. Double strands are held together by Watson-Crick interactions, so don’t form interactions that can be denatured. Whereas single stranded nucleic acids must be linearised.
During a southern blot procedure, whic of these elements oif the technique enables you to most definitely assess the presence of a DNA species of known size?
A. A size marker ladder electrophoresed alongside your sample.
B. A labeled oligonucleotide
B. A labeled oligonucleotide.
Knowing the size isn’t definitive proof, whereas the oligonucleotide would be specific to the DNA species.
How to tell if something is an expression vector?
Expression vectors have a promoter (usually CMV) upsteam of a GFP.
You would like to introduce a mutated gene of interest into a mammalian cell line and be able to study the functional effects over the course of several months. Which of these techniques would be most suitable?
A. Heat shock.
B. Lipofection.
C. Retrovirus mediated transfection.
C. Retrovirus mediated transfection
Enables the DNA of interest to integrate into the host genome, maing it stable and protecting it from nucleases.
The aim of your mouse Cre-LoxP engineering project is to “knock-out” a gene of interest specifically in the liver. Which one of these components would be practically relevant to your transgenics workflow?
A. Insertion of LoxP sites flanking the gene of interest specifically in the liver
B. Insertion of a Cre recominase gene into thte genome specifically in the liver.
C. A Cre recombinase gene under the control of a promoter that is specifically activated in the liver.
C. A Cre recombinase gene under the control of a promoter that is specifically activated in the liver.
Actually targets the liver as opposed to B, which isn’t specific. A is nice in theory, but must be very difficult to actually achieve, especially without a cre.
