Knockdown cells contain a functional loss of a gene. Methodologies including RNAi, TALEN, and CRISPR can be used to silence the gene depending on experimental needs. At TME, we predominantly use a CRISPR-based system which has been validated to produce effective knockdown of the target gene with minimal off-target effects. Depending on the characteristics of the cells and experimental goals, the most appropriate methodology (viral transduction, chemical transfection, or electroporation) is used for the transfection of Cas and sgRNA. The gene of interest can be constitutively turned off or regulated through a treatment (eg: tet-On system). The knock-down cells are validated and provided as cell pools or clonal cell lines. For the cell pools, the cells are selected by appropriate antibiotic selection and for the clonal line, the cells are sorted by FACS. All cells are validated by confirming the modification at the target location by sequencing. These cells are used for functional analysis of the gene, loss-of-gene-function studies, and disease modeling.