LwaCas13a Nuclease: A CRISPR-Based Enzyme for RNA Detection and Targeted RNA Cleavage

RNA plays a central role in genetic information transfer and gene expression regulation, making it an important target in pathogen detection, transcriptomic research, and molecular biology.

As RNA-based research and diagnostic technologies continue to advance, researchers need detection methods that combine sensitivity, specificity, and rapid signal readout. RT-qPCR offers high sensitivity but requires thermal cycling and appropriate sample preparation. Antigen-based rapid tests are easier to use but may not provide the sensitivity needed for certain applications.

CRISPR-Cas13a offers an alternative approach to RNA detection by coupling sequence-specific RNA recognition with target-activated collateral cleavage. This mechanism enables RNA recognition events to be converted into detectable fluorescence or lateral-flow signals.

Yeasen's LwaCas13a Nuclease (Cat. No. 14709ES) is a recombinant nuclease derived from Leptotrichia wadei, designed for RNA detection research and targeted RNA manipulation.

1. What Is LwaCas13a Nuclease?

LwaCas13a is an RNA-guided CRISPR-associated nuclease. Together with a CRISPR RNA (crRNA), it recognizes complementary target RNA and can trigger RNA cleavage.

Its activity can be broadly divided into two mechanisms:

• Cis-Cleavage: Targeted RNA Cleavage

The crRNA guides Cas13a to a complementary target RNA sequence. Upon target recognition, the nuclease cleaves the target RNA, subject to the requirements of the particular Cas13a system, including its target sequence and protospacer flanking site (PFS) preferences^[3].

• Trans-Cleavage: Target-Activated Signal Generation

Target RNA recognition activates Cas13a's collateral RNase activity, enabling it to cleave nearby single-stranded RNA molecules, including labeled RNA reporters. Reporter cleavage generates a detectable signal, allowing the presence of a target RNA to be reported^[4].

The distinction between these two activities is central to understanding Cas13a-based assays: cis-cleavage acts on the recognized target, while trans-cleavage provides the signal-generation mechanism used in many CRISPR RNA detection systems.

2. Key Applications of LwaCas13a

Building on these properties, LwaCas13a Nuclease is broadly applicable to the following scenarios:

High-sensitivity in vitro RNA detection
  Leveraging target-activated trans cleavage, LwaCas13a converts molecular-recognition events into amplifiable fluorescent or lateral-flow signals. Combined with isothermal amplification, it enables attomolar (aM)-level detection of viral RNA, pathogen RNA, and trace transcripts, making it a key enzyme for CRISPR nucleic-acid detection systems such as SHERLOCK ^[1,2].

Intracellular RNA targeting and knockdown

LwaCas13a can be heterologously expressed in mammalian and plant cells to target and degrade reporter genes or endogenous transcripts, achieving gene-expression knockdown ^[5].

Site-specific in vitro RNA cleavage

As a site-specific RNA cleavage tool, it is suited to RNA processing and in vitro molecular-manipulation experiments ^[6].

3. YEASEN LwaCas13a Nuclease (14709ES) data

Target-dependent, efficient trans cleavage that underpins signal amplification in RNA detection

Figure 2. Validation of LwaCas13a Nuclease trans-cleavage activity

Note: 1 ng/µL transcribed RNA, 1 U/µL Murine RNase Inhibitor; LwaCas13a Nuclease 1 pmol (final concentration 50 nM); DEPC water to 20 µL. Negative controls: (1) no transcribed RNA; (2) no crRNA. Incubated at 37°C with real-time fluorescence acquisition. Significant fluorescence arose only in the system where target RNA and crRNA coexisted, demonstrating that trans-cleavage activity requires co-activation by both crRNA and target ssRNA.

Triple nuclease-residual QC that reduces interfering-enzyme effects and improves experimental reproducibility

 Figure 3. Nuclease-residual detection results for LwaCas13a Nuclease

[Note]: The control (C) and LwaCas13a Nuclease were each incubated with the corresponding nucleic-acid substrate at 37°C for 4 h, followed by agarose gel electrophoresis. The sample bands were identical to the control, with no degradation or smearing attributable to residual endonuclease, exonuclease, or RNase.

Related products

Product Name	Cat. No.	Typical Application
LwaCas13a Nuclease (10 µM)	14709ES	crRNA-guided RNA endonuclease; Intracellular RNA targeting and knockdown In vitro RNA cleavage

References

[1] Gootenberg J S, Abudayyeh O O, Lee J W, et al. Nucleic acid detection with CRISPR-Cas13a/C2c2. Science, 2017, 356(6336): 438-442.

[2] Myhrvold C, Freje C A, Gootenberg J S, et al. Field-deployable viral diagnostics using CRISPR-Cas13. Science, 2018, 360(6387): 444-448.

[3] Abudayyeh O O, Gootenberg J S, Konermann S, et al. C2c2 is a single-component programmable RNA-guided RNA-targeting CRISPR effector. Science, 2016, 353(6299): aaf5573.

[4] East-Seletsky A, O'Connell M R, Knight S C, et al. Two distinct RNase activities of CRISPR-C2c2 enable guide-RNA processing and RNA detection. Nature, 2016, 538(7624): 270-273.

[5] Abudayyeh O O, Gootenberg J S, Essletzbichler P, et al. RNA targeting with CRISPR-Cas13. Nature, 2017, 550(7675): 280-284.

[6] Cox D B T, Gootenberg J S, Abudayyeh O O, et al. RNA editing with CRISPR-Cas13. Science, 2017, 358(6366): 1019-1027.

About YEASEN

Founded in 2014, YEASEN Biotechnology (Shanghai) Co., Ltd. is a high-tech enterprise focused on the upstream core raw materials of the life-science industry, dedicated to the R&D, manufacturing, and sales of biological reagents across four major categories — nucleotides, proteins, cells, and organoids. Combining proprietary core technologies with large-scale production capacity, YEASEN offers thousands of products spanning molecular cloning, qPCR, NGS, in vitro transcription, antibodies, protein purification and analysis, cell culture, transfection, reporter-gene assays, organoids, and GLP-1 core raw materials, serving life-science research, diagnostic testing, biomedicine, and broader healthcare.