Name: ProSpec Bio Recombinant S. Pyogenes CRISPR-Associated Protein-9 Nuclease
Brand: ProSpec Bio
SKU: PSB-ENZ-901
Availability: InStock

<h2 dir="ltr"> What Are Cas9 Enzymes?</h2>
 Cas9 is the catalytic core of the CRISPR/Cas9 editing system. Sourced from Streptococcus pyogenes (SpCas9) or Staphylococcus aureus (SaCas9), recombinant Cas9 proteins are expressed and purified to high purity for direct use in ribonucleoprotein (RNP) complexes &mdash; currently the most widely recommended format for mammalian cell editing due to rapid activity onset and minimised off-target effects compared to plasmid-based delivery. Genome-editing performance depends on the appropriate nuclease format. Choose the Cas9 enzyme that aligns with your editing strategy.
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<h2 dir="ltr">What you will find:</h2>
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NLS-Tagged Cas9 and saCas9 Nucleases: Recombinant proteins of high purity designed for quick nuclear localization and strong initiation of double-strand breaks (DSBs) at specific genomic sites.
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Precision Cas9 Nickase (H840A): Tailored variants created for dual-nicking approaches to improve genomic stability and notably minimize off-target alterations.
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Lyophilized Nuclease Preparations: Nuclease-free, shelf-stable proteins that offer optimal adaptability for reconstitution and high-throughput automated CRISPR-related processes.
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Catalytically Inactive Null Mutants: "Dead" Cas9 (dCas9) proteins designed for DNA-binding research and specific epigenetic modification without changing the original sequence.
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Cas12a (asCpf1) Nucleases: Alternative CRISPR systems that focus on T-rich PAM sequences to broaden the range of spatial transcriptomics and targetable genomic areas.
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GFP-Tagged Cas9 Proteins: Fluorescently marked nucleases developed for real-time assessment of transfection efficacy and visual verification of cellular absorption.
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Endotoxin-Free Enzyme Formulations: Highly pure mixtures crucial for preserving cell viability in sensitive lentiviral applications and primary cell modifications.
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<h2 dir="ltr"> How to Choose a Cas9 Enzyme</h2>
 PAM Requirement Wild-type SpCas9 recognises any genomic locus flanked by an NGG protospacer adjacent motif (PAM), occurring roughly every 8&ndash;12 bp in mammalian genomes. SaCas9 requires NNGRRT, though engineered PAM variants (KKH, KRH, KRKH) expand targetable space. Off-Target Sensitivity High-fidelity Cas9 variants carry substitutions in the recognition lobe that reduce non-specific DNA contacts, lowering off-target cleavage while maintaining on-target activity comparable to wild-type SpCas9 &mdash; recommended for therapeutic cell engineering and base editing. Editing Mechanism Wild-type SpCas9 generates a blunt double-strand break repaired by NHEJ (indels for knockout) or HDR (precise insertions). Nickase (D10A) cuts only one strand for paired-nick HDR strategies with reduced off-target indels. dCas9 carries mutations in both nuclease domains, enabling CRISPRa/CRISPRi gene regulation without DNA cleavage. AAV Compatibility SaCas9, at approximately 1 kb smaller than SpCas9, fits a complete Cas9 + sgRNA expression cassette within the ~4.7 kb AAV packaging capacity &mdash; enabling single-vector in vivo delivery without split-vector complexity. Storage and Handling Recombinant Cas9 proteins are supplied for stability during shipping and short-term storage at &minus;20 &deg;C or &minus;80 &deg;C. Repeated freeze-thaw cycles reduce activity; aliquoting upon receipt is recommended.
<h2 dir="ltr"> Specifications Context</h2>
 An RNP is a pre-formed complex of recombinant Cas9 protein and sgRNA; once electroporated, it acts immediately and is degraded within hours, reducing off-target cleavage and avoiding immune stimulation associated with plasmid or mRNA delivery.&nbsp;Recombinant Cas9 in RNP format is validated across HEK293, HeLa, iPSCs, T cells, primary neurons, and hepatocytes, though electroporation parameters typically require cell-type-specific optimisation. Product offerings reflect MBP's catalogue as of mid-2026. 
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Reach out to the supportive <a href="https://mbpinc.net/contact-us" style="color: #236fa1;">team at MBP Inc.</a> now to obtain a quotation for the perfect Cas9 enzyme for your study.

Cas9 Enzymes

ProSpec Bio

Key Specifications

ProSpec Bio Recombinant S. Pyogenes CRISPR-Associated Protein-9 Nuclease

Recombinant S. Pyogenes CRISPR-Associated Protein-9 Nuclease by ProSpec Bio is recombinant Cas9 nuclease with nuclear localization sequence produced in E. coli with a His tag at the C-terminus, a 1368-amino-acid protein of 163 kDa that is more than 90% pure. It is supplied as a solution in 50 µg, 100 µg and 500 µg sizes for genome editing research.