PREP 2018: CRISPR CAS9 Lab
Before even starting this internship, CRISPR was one of the subjects that I was most excited to learn about and experiment with. It definitely lived up to my expectations!
What is CRISPR?
Clustered regularly-interspaced short palindromic repeats, or CRISPR, is an innovative new genetic engineering tool, derived straight from the ‘immune systems’ of bacteria. With CRISPR, scientists can easily make cuts, edits, additions and deletions to genomes, eradicating harmful genetic diseases and potentially saving millions of lives.
How It Works
An enzyme known as Cas9, found in bacteria, has the ability to recognize and cut out fragments of DNA from its host. Evolutionarily, this was helpful in helping the bacteria survive repeated viral attacks, as viruses often hid their own DNA among that of the bacteria. Research has since shown that Cas9 can be ‘programmed’ to recognize different sequences of DNA, which means that it can be put in other organisms to recognize segment of DNA that require editing.
The Lab
To better understand how scientists use this tool to advance treatments and medicine, we had to perform a CRISPR lab ourselves!
The idea was to follow the process through its course; from choosing the location of the cut in the DNA, to seeing how the different fragments of DNA would separate. Our process began on the computer, using nucleotide databases to map out where the enzyme would cut the our DNA, which codes for a tumor-suppressing gene (BRCA1). This gave us an accurate prediction of how long each piece of DNA would be, based on where it was cut.
Once in the lab, we combined the Cas9 enzyme with an RNA (ribonucleic acid) guide, which would serve as the ‘programmer’. We then introduced our gene, and allowed the enzyme to sever the DNA sequence. After removing the Cas9 from the solution with yet another enzyme, we separated the fragments using electrical currents. DNA is negatively charged, so after a current is run through it, the fragments will move toward a positive anode. After a while, it’s easy to see how the little pieces of DNA have moved apart as they travelled toward the positive charge!
CRISPIER
Unlike pipettes, microscopes, or any other tool that can be found in a high school laboratory, CRISPR is still extremely new technology. Until now, I didn’t have any idea as to what CRISPR was or what it did, other than the notion that it was ‘revolutionary’. The opportunity to learn about and experience a new scientific breakthrough is a great opportunity, and already has the gears in my head spinning about what it can do next. This kind of exposure was a huge highlight of these two weeks, and while I may have come here knowing nothing about CRISPR, I left with plenty of information that made my understanding much crispier.
