EDITGENE provides access to a comprehensive library of over 4,500 high-quality knockout (KO) cell lines, enabling researchers to save valuable time. Our custom gene knockout services are highly efficient, boasting a high positive rate while minimizing off-target effects. Clients also benefit from personalized, one-on-one support from a team of PhD experts from globally renowned institutions, ensuring top-tier service and results.

KO cell lines can be applied to various cell types, including cancer cells, stem cells, and primary cells, but different cell types may have varying sensitivities to gene editing, and may vary among different cell types. In certain cell types, achieving gene knockout may require optimization of transfection conditions and selection of appropriate gene-editing tools.

KO (Knockout) cell line is a cell line where a specific gene has been completely removed or rendered non-functional through gene editing technologies such as CRISPR-Cas9. These cell lines are critical for understanding gene functions and disease mechanisms.

Not all genes are suitable for knockout. Some gene knockouts may result in cell death or severe dysfunction, particularly for essential genes. In such cases, conditional knockouts or gene knockdowns (e.g., RNAi) may be used instead.

The main difference lies in the duration and stability of gene expression: Transient cell line – The target gene is expressed temporarily in cells, typically lasting hours to days, and is suitable for short-term experiments. Stable cell line – The target gene is stably integrated into the cell genome, allowing long-term expression, suitable for extended research and production.

1.Design an efficient crRNA sequence. Proper design and structure prediction using online resources can help select suitable crRNA to achieve good trans-cleavage activity of the Cas enzyme.
2.Choose an appropriate signal reporter substrate. Research indicates that using a 15 nt single-stranded DNA (ssDNA) as a reporter substrate maximizes the cleavage reaction rate of Cas12a, significantly enhancing the reaction rate compared to the commonly used 5-nt ssDNA.
3.Optimize reaction conditions and buffers. Adjusting the CRISPR reaction parameters, such as the ratio of Cas enzyme to crRNA, the concentration of the Cas enzyme, and the reaction temperature, can improve detection performance to some extent.

Maintaining the activity of cell cultures is crucial. Cells should not be allowed to reach confluence for more than 24 hours. Frozen new cells can restore transfection activity. The optimal cell plating density varies for different cell types or applications; however, for adherent cells, a confluence of 70% to 90% or a density of 5×10^5 to 2×10^6 suspended cells/ml typically yields good transfection results. It is important to ensure that cells are not fully confluent or in a fixed phase during transfection.

Lentivirus is a gene delivery tool that introduces exogenous genes into cells. By using tool cells such as 293T, lentiviral vectors carrying target DNA fragments are packaged into lentiviral particles with cell-infectious activity. This packaging process includes constructing lentiviral vectors, preparing packaging plasmids, culturing tool cells, transfecting plasmids, collecting viral particles, purifying and concentrating viral particles, and titration.

What is the difference between a single-plasmid system and a dual-plasmid system for library vectors? A single-plasmid system can achieve gene editing with one transfection, making construction relatively simple, but the larger plasmid size can lead to lower infection efficiency. In a dual-plasmid system, two vectors are used, each carrying either the Cas9 or sgRNA expression cassette. A stable Cas9 cell line is first constructed, and then the sgRNA library is transfected into this cell line. This approach has several advantages:
1.Increased Editing Efficiency: The independent and stable expression of Cas9 protein and sgRNA on different vectors enhances editing efficiency.
2.Flexibility: Vectors can be designed and constructed flexibly based on experimental needs, such as loading two sgRNA expression cassettes into one vector.
3.Increased Viral Titer: By splitting into two plasmids, the load on each plasmid is reduced, facilitating viral packaging and increasing yield and titer.
4.Increased Stability: Independently constructing a stable Cas9 cell line ensures that the Cas9 expression levels and editing efficiency in each cell are approximately the same, enhancing experimental accuracy.

1.The design process can follow these steps:
1.Identify the target gene sequence.
2.Specify the Cas protein being used. Different Cas proteins require corresponding PAM (Protospacer Adjacent Motif) sequences; for instance, Cas12a needs the "TTTV" PAM sequence for target recognition.
3.Select the crRNA targeting region. Choose a 20 nt nucleotide sequence on the target gene that is adjacent to the PAM site and pairs with the complementary strand of the crRNA.
4.Combine the selected 20 nt target sequence (variable part) with the scaffold sequence (fixed part) to design the crRNA sequence.
5.Use online tools such as CRISPR design tools (e.g., CRISPOR, Benchling, etc.) to assist in designing crRNA. These tools can predict the efficiency and specificity of the sgRNA, helping to avoid potential off-target effects.
6.After completing the design, the synthetic crRNA sequence can be ordered from a synthetic biology company.

EDITGENE’s 3D single-cell printing technology employs non-contact operation, avoiding mechanical damage and background contamination, which helps maintain cell integrity and biological activity. This technology also minimizes human error in the traditional limited dilution method of monoclonal selection, ensuring the reliability of screening results.