GeneArt™ Platinum™ Cas9 Nuclease (1 µg/µL) - FAQs

View additional product information for GeneArt™ Platinum™ Cas9 Nuclease (1 µg/µL) - FAQs (B25640)

13 product FAQs found

How do I check for off-target effects in my CRISPR-modified cell lines?

The only complete way to confirm that there are no off-target effects is to sequence the entire genome of your cell. Alternatively, a less thorough means of checking for off-target editing is to perform targeted sequencing of sequences with the highest probability of off-target effects (i.e., most similar to your CRISPR target region).

How many guide RNAs do you recommend designing against my desired edit locus?

A single guide RNA (gRNA) is all that is required for targeting, but we do recommend testing 2-3 gRNAs against each locus being targeted for cleavage. Testing multiple gRNAs increases the chances of finding a gRNA with high editing efficiency, which will reduce the screening time required to identify the clone of interest.

How should the Cas9/gRNA ribonucleoprotein (RNP) complex be transfected into cells?

We recommend using the Neon Transfection System or the Lipofectamine CRISPRMAX Cas9 Transfection Reagent.

How much Lipofectamine CRISPRMAX Reagent, Cas9 protein, and gRNA should I complex for gene editing?

Please see the Lipofectamine CRISPRMAX Reagent manual (https://assets.thermofisher.com/TFS-Assets/LSG/manuals/MAN0014545_lipofectamine_crispermax_QR.pdf) for protocol details or contact techsupport@thermofisher.com.

How does the Lipofectamine CRISPRMAX Reagent work?

The Lipofectamine CRISPRMAX Reagent combined with the proprietary enhancement properties of the Lipofectamine Cas9 Plus Reagent leads to efficient complex formation with the Cas9-gRNA ribonucleoprotein, for best delivery to the nucleus, helping to ensure high gene editing frequency for a wide range of cell types.

Can the Lipofectamine CRISPRMAX Reagent be used to deliver proteins other than the Cas9 nuclease?

Although the Lipofectamine CRISPRMAX Reagent was developed for the delivery of the Cas9-gRNA ribonucleoprotein, there is potential for other protein complex applications.

Can the Lipofectamine CRISPRMAX Reagent also be used to deliver the donor plasmid in addition to the Cas9 nuclease protein and gRNA?

The Lipofectamine CRISPRMAX Reagent was developed to efficiently deliver the Cas9-gRNA ribonucleoprotein complex. We recommend that you first deliver the donor plasmid with Lipofectamine 3000, then follow with delivering the Cas9-gRNA complex with Lipofectamine CRISPRMAX Reagent for best editing efficiency.

What transfection methods do you recommend when working with your CRISPR products?

For transfecting of the Cas9 protein, we would recommend using the Neon transfection system or Lipofectamine CRISPRMAX Cas9 Transfection Reagent. For transfection of mRNA, we would recommend using Lipofectamine MessengerMAX Transfection Reagent. For transfection of CRISPR vectors, we would recommend using Lipofectamine 3000 Transfection reagent.

Find additional tips, troubleshooting help, and resources within our Transfection Support Center.

Do you have CRISPR products optimized for plants?

Our CRISPR products are optimized for mammalian systems, and have not been optimized for plant systems. However, we know researchers are doing that kind of work. While we have not tested our CRISPR products for plants, our new protein format would be ideal since it does not need to be translated and transcribed in the cell, so no plant-specific promoters required.

What is the buffer composition for the Platinum Cas9 protein?

The buffer composition for the Platinum Cas9 protein is as follows:
10 mM Tris-HCl pH 8.0, 150 mM NaCl, 0.6 mM TCEP, 50% glycerol. Please note that we can make custom formulations if necessary.

What gRNA controls do you recommend?

The Precision gRNA Synthesis Kit (Cat. No. A29377) includes primers for synthesis of gRNA targeting safe harbor locus HPRT. We also have a fully processed, fully validated HPRT gRNA with GCD primers for confirmation of cleavage available from our custom services team.

Can you provide suggestions on how to introduce a fragment into the genome or important sequence by HDR (homology directed repair)?

Create a double-stranded DNA break using the GeneArt CRISPR Nuclease Vector (https://www.thermofisher.com/us/en/home/life-science/genome-editing/geneart-crispr/crispr-nuclease-vector.html), while simultaneously transfecting your plasmid-based donor repair template. Your donor repair template plasmid will contain the sequence you wish to introduce that is flanked by at least 500 bp (or more) of sequence, which results in efficient homologous recombination of your sequence.

What is most efficient for HDR (homology directed repair), and what length is recommended for the homologous exogenous DNA, single-stranded oligos, double-stranded oligos, or large homologous arms (>1 kb) from a plasmid?

All of them may work, but for better efficiency, a longer homology arm is better (at least 500 bp (or more) on either side of the exogenous DNA). The homology length is dependent on the size of the fragment and will need to be tested. ssDNA may be error-prone or choose NHEJ. We offer the Invitrogen GeneArt Strings dsDNA fragments (1-3 kb) to assist with this type of application.