Targeted genome editing in mammalian cells – CRISPR/Cas9 makes it possible


Targeted genome editing with the hope of treating and curing diseases has always been a major goal in the field of biology. The groundbreaking discovery of CRISPR/Cas9 technology has opened up a wealth of avenues for innovative research to get closer to realizing this goal. CRISPR/Cas9 is a “genome editing” tool that extends gene therapy by not only potentially delivering healthy copies of genes, but rewriting the bad ones too. However, developing specific methods for efficient and safe delivery of this technology to cells and tissues and limiting off-target effects is essential for the future of gene therapy. Here we’ll be giving an overview of this exciting technology and outlining two new methods for using it in tissue culture.

A brief history

Back in the 80’s researchers noticed that bacterial genomes contain small blocks of repeating DNA separated by non-repeated “spacers” of stored DNA. These spacers are pieces of viral DNA that the bacteria keep as a record of the viruses they have been exposed to. It works like an immune system, and is known as CRISPR (clustered regularly interspaced short palindromic repeats). In brief, when a virus invades the bacteria, the spacer DNA is converted into RNA. A protein, known as Cas9, binds to this RNA to form a complex which then binds to the matching sequence in the genome of the invading virus. Cas9 opens the helix and cuts both sides of the DNA – disabling the virus. Researchers figured out that they could manipulate this process by making synthetic RNA strands which could be used to add or delete specific bits of the genome (1).

Developing specific and stable methods for all

Last year, two exciting protocols were published describing how to use CRISPR technology in tissue culture (Figure 1). The first describes how to perform viral packaging and cell culture for CRISPR-based screens (2) and the second describes how to use CRISPR technology for genome activation and repression in mammalian cells (3). Both methods combine the expertise of researchers in CRISPR/Cas9 technology with our robust purification solutions, such as our Plasmid Midi Kit, which purifies plasmid DNA using an endotoxin-free protocol for better transfection efficiency (3). It’s protocols such as these that will enable labs across the globe to better understand complex gene networks and functions and apply CRISPR/Cas9 technology in a standardized way to future medical and industrial advances.

Find out how your research could benefit from this new technology by visiting our CRISPR/Cas9 gene editing website.


Figure 1. A. Workflow for performing viral packaging and cell culture for CRISPR-based screens. B. Workflow for using CRISPR technology for genome activation and repression in mammalian cells.


  1. 1. Hsu, Patrick D. et al 2014. Development and Applications of CRISPR-Cas9 for Genome    Engineering. Cell. 157, 1262.
    2. Wang T. et al. Viral Packaging and Cell Culture for CRISPR-Based Screens 2016; pdb.prot090811
    3. Du Dan, Qi S. Lei. CRISPR Technology for Genome Activation and Repression in Mammalian Cells  2016. Cold  Spring Harb Protoc. 349, 205.
Kjell Kirschbaum

Kjell Kirschbaum, M.Sc., is a Global Market Manager based in QIAGEN’s Venlo office, the Netherlands. He trained as a bioveterinary scientist at the University of Utrecht and has hands-on experience in nucleic acid and protein purification, cell culture, PCR and qPCR technology. Kjell joined QIAGEN in 2011 as a CRM specialist, regularly interacting with customers about their day-to-day experimental needs and offering relevant solutions. Currently, he is involved in managing global projects for sample preparation and automation technologies.

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