Week 2 Study Guide: Gene Editing

Methods in Cell Biology – 

Learning Objectives


Assigned reading: 

Readings on Canvas

And Brooker Biology 6th ed: p445-459


NOTE ABOUT PRE-CLASS STUDY GUIDE: The learning objectives in italics do not need to be included in this week’s pre-class study guide. 


From Brooker Biology reading


  • Describe and explain the basic techniques and tools of genetic engineering—specifically, digestion by restriction enzymes, plasmid cloning, transformation, and PCR. 


  • Restriction enzymes: Restriction enzymes come from bacteria’s defense mechanisms in which certain segments of viral DNA are cut. These are useful in genetic engineering because they allow for both plasmids and genes of interest to be cut at particular points.

  • Plasmid cloning: Plasmids are cloned through the propagation of bacteria containing recombinant plasmids. This often includes having selectable markers to verify if a successful plasmid insertion has been done.

  • Transformation: The alteration of a plasmid to form a successful differing end result that expresses a new gene.

  • PCR: Another process to amplify DNA without host cells. It begins with the use of a forward and reverse primer, around 20 nucleotides long, that is complementary to DNA sequences at the end of each side of the gene of interest. Then, through separating the DNA strands, primer annealing can occur, then DNA polymerase will come and build the rest of the DNA. Each step requires a different set temperature.


  • Describe how you would isolate a gene and clone it into a vector and identify transformants of interest.  


  • To do so, restriction enzymes would first cut out the gene of interest. Then, through PCR, the DNA would be amplified. Then, restriction enzymes would be used once again to insert the gene of interest with a selectable marker to ensure verifiability in the cells of chosen insertion.


From the Additional Reading


  • Describe what antibodies are, and provide several examples of how they can be used in cell biology research. 


  • An antibody is an adaptive immune response found in the bloodstream. They bind to antigens to protect the body. They can be used in cell biology research by allowing scientists to more easily study specific antigens.


  • Describe basic techniques of cell biology including western blotting, co-immunoprecipitation, immunofluorescence, and GFP tagging. Be able to describe what types of questions these techniques can answer, how these techniques are done, and how to interpret data from them. Describe strengths and limitations of cell biology techniques.


  • In Western blotting, proteins are able to be extracted from a complex mix and identified through first separation by size, then the transfer to a solid support, and lastly, using antibodies to mark target proteins. Immunoprecipitation is a technique used to isolate and purify a specific protein with the help of antibodies and antigens. Co-immunoprecipitation is done rather with a group of proteins instead. GFP tagging works by inserting a green fluorescent protein into an organism in order to track something. It is very useful as it allows scientists to track stuff in real time.


Which concept or element of this chapter did you find the most difficult?


  • I think all the talk about antibodies and immunofluorescence was difficult for me to comprehend.


Are there any issues or concerns that you have about this section or the course in general?


  • I am a little concerned that my knowledge on these new forms of protein extraction techniques is a quite lackluster.