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SARS CoV-2 3CL Protease Substrate, Rh110-conjugated

Bio-Techne includes R&D Systems | Catalog # S-720

Catalog #
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Key Product Details




Rhodamine 110



Product Specifications


Chemically Synthesized
LGSAVLQ-rhodamine 110-dP


>95%, by HPLC. 1096.6 Da

Predicted Molecular Mass

1096.3 Da


LGSAVLQ-Rh110-dP is a fluorogenic substrate for measuring the 3CL protease activity of coronaviruses.  The sequence is derived from the SARS CoV-2 3CLpro.  Release of Rhodamine 110 can be monitored with excitation and emission wavelengths of 485 nm and 535 nm, respectively.  Conditions will need to be optimized for each specific application.  We recommend an initial substrate concentration of 4-20 μM.

Formulation, Preparation and Storage

Formulation 4 mM in DMSO
Shipping The product is shipped with polar packs. Upon receipt, store it immediately at the temperature recommended below.
Stability & Storage Protect from light. Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
  • 12 months from date of receipt, -20 to -70 °C as supplied.
  • 6 months, -20 to -70 °C under sterile conditions after opening.

Background: 3CL Protease

The 3CL protease (aka 3CLpro, Mpro or "Main" Protease) from the human SARS-CoV-2 coronavirus (Severe Acute Respiratory Syndrome coronavirus 2) is a C30-type cysteine protease located within the non-structural proteins 3 (NS3) section of the viral polypeptide.  3CLpro activity is required to process the viral polyprotein into functional, mature subunits, and there are 11 or more sites of cleavage, many containing the sequence LQ[S/A/G]; the protease cleaves c-terminal to the glutamine amino acid.  Along with the CoV-2 Papain-Like Protease (catalog number E-611), 3CLpro presents an attractive target for therapeutic intervention for COVID-19.  Because no human proteases with a similar cleavage specificity are known, inhibitors of 3CLpro are unlikely to cause mechanism-based toxicity.

This peptide substrate (LGSAVLQ-Rh110-dP) contains a naturally occurring cleavage site for SARS-CoV-2 3CL protease conjugated to a Rhodamine 110 dye.  3CL protease activity releases the dye to fluoresce with high signal-to-background ratios in either kinetic or end-point assays.


  1. Chen Y.W., et al. (2020) F1000Research  doi: 10.12688/f1000research.22457.2
  2. Pillaiyar T., et al. (2016) J. Med. Chem.  59: 6595
  3. Zhang L., et al. (2020) Science  doi: 10.1126/science.abb3405

Long Name

3CL Protease

Alternate Names

Main Protease, Mpro

Additional 3CL Protease Products

Product Documents for SARS CoV-2 3CL Protease Substrate, Rh110-conjugated

Certificate of Analysis

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Note: Certificate of Analysis not available for kit components.

Product Specific Notices for SARS CoV-2 3CL Protease Substrate, Rh110-conjugated

For research use only