CRISPR (Clustered Regularly Inter Spaced Palindromic Repeats) is a type of immune system mechanism that bacteria and archaea use to protect their genomes from viruses. Within CRISPR sequences, there is a memory carrying the nucleic acids of invasive organism/s. As a foreign DNA enters into cell, it is compared to this CRISPR memory, if there is a match, invasive DNA is readily cleaved by Cas9 endonuclease under crRNAs guidance. Inspired from this phenomenon, scientists created a single guide RNA (sgRNA) by reshaping crRNAs that guide Cas9 endonuclease. Thus, it was possible to perform a targeted genome editing or gene knockout in any desired location of the genome. However, CRISPR system has some disadvantages. To overcome this, target-edit validation and off-target detection are a must.
In this regard, next generation sequencing (NGS) systems provide high precision target-edit validation and off-target detection with a reasonable price. CRISPR amplicon sequencing, in particular has become a standard validation/detection method in clinical, industrial and academic applications.