CRISPR knockout requires expression of both a single-guide RNA (sgRNA) that targets the specific site for knockout, and expression of the Cas9 nuclease which cuts the DNA at the target site. Also, for studies using the CRISPRa or CRISPRi systems, cells need to express the corresponding dCas9 activator (e.g. dCas9-VPH or dCas9-VPR) or dCas9-repressor (e.g. dCas9-KRAB). For many CRISPR applications then, it is useful or necessary to have cells stably expressing one of the the Cas9 proteins.
After you let us know what Cas9 variant you want in what cell lines, Cellecta will transduce and test the target cells at multiple MOIs to produce healthy cells with optimal expression of the Cas9 protein. Cellecta not only makes stably expressing Cas9 or dCas9-activator/repressor cell lines, but validate the activity of the Cas9 protein in the cells using the functional CRISPR-Cas9 activity Assay. You receive stable Cas9-expressing cells with Cas9 activity level data.
We are offering the following cell line engineering options:
inducible or constitutively Cas9 expressing cell line of your choice
Knockout or knockdown a gene
Zero-footprint CRISPR knockout using non-integrated sgRNA and Cas9
Inducible gene activation and inhibition with CRISPRa and CRISPRi
Knock-in genes or gene-tags
2. Custom Engineered Cell Lines
Pick the cells and modifications you want and we do the work. Although we rely heavily on CRISPR mediated engineering since it is so versatile and powerful, we have experience with a range of technologies for cell engineering. Depending on your application, knockouts, knock-ins, knockdowns, or some combination of these may be required.
We provide validated cell pools or clonal cell lines. For the cell pools, we sequence and confirm modifications at the target location. For clonal lines, we characterize the specific indels or insertions present in each allele and, for knockout cells in particular, check for the presence of the wild-type allele since many common cell lines are polyploid.
Transcription factor-dependent reporter cell lines can be ideal tools for high-throughput RNAi, peptide, and chemical library screens. Responsive reporter cells form the core of cell-based assays for screening and identifying drugs, antibodies, cell factors, and other effectors. With lentiviral-based transduction, Cellecta can easily engineer stable reporter lines for almost any application–regardless of cell type.