For robust SAM transcription activation, gRNAs must target the first 200 bp upstream of the transcription start site (TSS). To decrease the degree of transcription activation, design gRNAs that target the SAM complex to greater distances upstream of the TSS. To repress transcription, design gRNAs that target SAM to +50 relative to the TSS, which will effectively block the TSS.
GenScript maintains a genome-wide SAM gRNA database which contains 6 SAM gRNAs designed to activate each coding region of the human genome. For other species, our scientists offer complimentary SAM gRNA design help. Request custom SAM gRNA design here.