Here at CiteAb we’re always interested to learn more about antibodies and those technologies that use them or have an impact on their use.
For that reason, this week we’re taking a brief look at the CRISPR-CAS immune system and how more recently it has been harnessed as a technology for use in highly specific gene editing and of course how this all relates to antibodies.
What is CRISPR-Cas
Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) in the DNA and CRISPR Associated (Cas) proteins are a widespread bacterial and archaeal defence mechanism against invading genetic elements. First discovered in 1987, it was a number of years before the role of CRISPR-Cas as a defense mechanism was elucidated.
Appearing as arrays of short unique nucleotide spacer sequences interspersed within the CRISPR palindromic repeat regions. These spacers act as a record of previous encounters with foreign genetic elements and provide to the bacteria/archaea (when processed by Cas) the ability to degrade those foreign genetic elements containing the same sequences. In this way CRISPR-Cas endow bacteria/archaea with an adaptive response to pathogens. Along with providing a defence mechanism, there is also evidence that CRISPR-Cas may also play a role in bacterial pathogenesis.
Why Pay Attention to CRISPR-Cas
CRISPR-Cas as a technology for gene editing and protein knockout, is a relatively recent development and provides an alternative to the already available transcription activator-like effector nucleases (TALEN) and zinc finger methods. Unlike it’s predecessors which rely on generating custom proteins for each DNA target, CRISPR-Cas technologies rely on guide RNA molecules making them more versatile and facilitates the generation of large libraries of CRISPR-Cas transcription factors.
How are CRISPR-Cas Relevant to Antibodies
Successful validation of an antibody depends on being able to demonstrate that the reagent is specific, selective, and reproducible in the context for which it is intended to be used. One method by which an antibody can be validated as being specific to a target protein is by comparing wild type and knockout samples: CRISPR-CAS protein knockout can be used to create the knockout cell line which will be used as a negative control. This makes validation particularly simple, when using Western blotting for example one would expect (hope!) that the target protein band is no longer present.
So there we have it, an introduction to CRISPR-CAS! What are your opinions on CRISPR-CAS and the potential of the technology? Do you currently utilise CRISPR-CAS in your research? We’d love to hear from you – leave a message below or send us a tweet to @CiteAb!
– Matt and the CiteAb team.
Front page image: Crystal structure of a hypothetical protein tt1823 from thermus thermophilus. from Wikipedia
First image: Diagram of the possible mechanism for CRISPR. from Wikipedia
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