CRISPR Technology

CRISPR (clustered regularly interspaced short palindromic repeats) technology is a simple yet powerful tool for editing genomes. It allows researchers to easily alter DNA sequences and modify gene function. Its many potential applications include correcting genetic defects. In popular usage, “CRISPR” (pronounced “crisper”) is shorthand for “CRISPR-Cas9.” CRISPRs are specialized stretches of DNA. The protein Cas9 (or “CRISPR-associated”) is an enzyme that acts like a pair of molecular scissors, capable of cutting strands of DNA. CRISPR technology was adapted from the natural defense mechanisms of bacteria and archaea (the domain of single-celled microorganisms). These organisms use CRISPR-derived RNA and various Cas proteins, including Cas9, to foil attacks by viruses and other foreign bodies. They do so primarily by chopping up and destroying the DNA of a foreign invader. When these components are transferred into other, more complex, organisms, it allows for the manipulation of genes, or “editing.”

Mr. Niglio’s Genetics students used CRISPR to edit the genomes of E. coli bacteria. They cultured the bacteria in agar containing Kanamycin and Streptomycin and if bacteria grew we knew the CRISPR did its job because the target of CRISPR in this case was to incorporate the genes to produce the enzymes for resistance to the antibiotics. If the experiment was successful the bacteria would be able to grow in the presence of antibiotics. The results can be seen in the picture. Each spot on the agar represents a bacterial colony that is grown in the presence of antibiotics. 

It’s really exciting to be able to use this cutting edge genetics technique that’s at the center of so much current research. It’s also interesting to discuss the ethics of how it should be used.