Crispr Screening
Crispr Screening - Related Videos
03:48
Screening for Genomic Modifications: A Method to Identify CRISPR-Generated Mutants in Drosophila
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2023
This video describes a screening method to identify transgenic Drosophila flies, whose genome was modified using CRISPR-Cas9. CRISPR-Cas9 is a powerful genome-editing tool that revolutionized the way scientists can manipulate an organism's genome. In the example protocol, we will see how to identify CRISPR-generated mutants, in which an insertion of a transactivation sequence replaces the first exon of the branchless (bnl) gene, thus creating a bnl gene-specific driver line, bnl-LexA.
12:25
Epigenome-Wide CRISPR-Cas9-Based Knockout Screens on Chemoresistant Cells
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2026
Here, we present a protocol for generating chemoresistant cells using a dose-escalation approach, followed by a CRISPR/Cas9-based screen using a focused sgRNA library targeting epigenetic modifiers to identify regulators of acquired chemoresistance. The protocol also provides multiple optimization points tailored to chemoresistant cell models, offering a robust framework for researchers investigating resistance mechanisms.
02:53
CRISPR and crRNAs
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2020
Bacteria and archaea are susceptible to viral infections just like eukaryotes; therefore, they have developed a unique adaptive immune system to protect themselves. Clustered regularly interspaced short palindromic repeats and CRISPR-associated proteins (CRISPR-Cas) are present in more than 45% of known bacteria and 90% of known archaea. The CRISPR-Cas system stores a copy of foreign DNA in the host genome and uses it to identify the foreign DNA upon reinfection. CRISPR-Cas has three different...
11:53
Substrate Generation for Endonucleases of CRISPR/Cas Systems
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Cited by 4 •
2012
CRISPR/Cas systems mediate adaptive immunity in Bacteria and Archaea. Many Cas proteins are proposed to act as endoribonucleases acting on crRNA precursors of varying length. Here we illustrate three different approaches to generate pre-crRNA substrates for the biochemical analysis of Cas endonuclease activity.
00:09
Pooled CRISPR-Based Genetic Screens in Mammalian Cells
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Cited by 13 •
2019
CRISPR-Cas9 technology provides an efficient method to precisely edit the mammalian genome in any cell type and represents a novel means to perform genome-wide genetic screens. A detailed protocol discussing the steps required for the successful performance of pooled genome-wide CRISPR-Cas9 screens is provided here.
FAQs
The choice of effector determines whether the screen primarily disrupts genes or changes their regulation. Cas9 can be used to interfere with gene function, whereas dCas9 and other CRISPR effectors support regulatory alterations without necessarily disrupting the underlying DNA sequence. This distinction allows researchers to examine both gene necessity and the consequences of altered gene expression.
Guide RNA libraries provide the collection of distinct genetic perturbations tested across many cells in parallel. Each guide directs a CRISPR effector toward a particular gene or regulatory target, allowing the resulting cellular response to be associated with that perturbation. The breadth of the library determines how extensively the screen can survey genetic contributions to a phenotype.
After cells experience a defined condition, sequencing shows which guide RNAs increase or decrease in representation. Enriched guides identify perturbations associated with improved survival or another selected outcome, while depleted guides indicate perturbations that reduce representation under the same condition. Comparing these patterns links specific genetic changes with condition-dependent cellular traits.
A typical workflow begins by delivering a guide RNA library together with Cas9, dCas9, or another CRISPR effector. Researchers then expose the perturbed cells to a defined selection condition and collect the resulting population for sequencing. They interpret guide enrichment or depletion to identify genes connected with the measured cellular response and prioritize candidates for follow-up studies.
This approach is useful when researchers need to test many genes simultaneously for effects on a disease-related cellular trait, response to a drug, or development of resistance. The resulting perturbation patterns can reveal genes that influence the phenotype and help organize them into functional pathways, providing candidates for mechanistic investigation or therapeutic target evaluation.
In genetics, the combined guide-level results can generate functional maps rather than isolated gene lists. Genes producing related effects under the selected condition may point to shared cellular functions or pathways. These maps help connect genetic perturbations with broader biological processes, identify essential cellular functions, and guide later experiments designed to examine mechanisms in greater detail.