Product Description:
The ScriptCap™ Cap 1 Capping System provides both ScriptCap™ Capping Enzyme and ScriptCap™ 2'-O-Methyltransferase allowing users to produce either a Cap 0 or Cap 1 cap structure on the 5' end of in vitro transcribed (IVT) RNA. ScriptCap™ Capping Enzyme catalyzes three enzymatic reactions: (1) conversion of the 5′-triphosphate of RNA to a diphosphate, (2) joining of GTP to the 5′-diphosphate of the first nucleotide and (3) methylation of the 7-nitrogen of guanine using S-adenosyl-methionine (SAM). These reactions produce Cap 0-RNA which can then be methylated to Cap 1-RNA through the simultaneous use of ScriptCap™ 2’-O-Methyltransferase. The system ensures nearly 100% 5’ capping efficiency, a level that cannot be obtained using co-transcriptional capping methods.
5’ Capping enhances mRNA stability and translation efficiency in cells compared to uncapped RNA, with Cap 1 methylation further boosting in vivo translation efficiency. A standard reaction caps 60 μg of RNA to Cap 0- or Cap 1-RNA in a single, 45-minute reaction and can be scaled up or down to accommodate user needs.
ScriptCap™ capped RNA can be added directly to A-Plus™ Poly(A) Polymerase tailing reactions without cleanup for seamless synthesis of fully 5’ capped and 3’ poly(A) tailed mRNA.
Materials Supplied:
Important Store at -20°C in a freezer without a defrost cycle. Do not store at -70°C.
ScriptCap™ Cap 1 Capping System Contents |
Kit Component |
Reagent Volume |
C-SCCS1710 -
10 Reactions |
C-SCCS2250 -
50 Reactions |
ScriptCap™ Capping Enzyme, 10 U/μl |
40 μl |
200 μl |
ScriptCap™ 2'-O-Methyltransferase, 100 U/μl |
40 μl |
200 μl |
10X ScriptCap™ Capping Buffer
0.5 M Tris-HCl, pH 8.0, 60 mM KCl and 12.5 mM MgCl2 |
100 μl |
500 μl |
10 mM GTP |
100 μl |
500 μl |
20 mM S-adenosyl-methionine (SAM) |
50 μl |
250 μl |
ScriptGuard™ RNase Inhibitor, 40 U/μl |
25 μl |
125 μl |
RNase-Free Water |
0.67 ml |
3.35 ml |
Materials Required, but not Supplied
- IVT RNA
- Materials or kits for purification of the RNA product
Terms & Conditions: The Product listed is currently offered by CELLSCRIPT™ for research use only under the defined Terms and Conditions.
FAQs: For answers to Frequently Asked Questions about our products, visit the FAQ library.
Still have questions? Our mRNA experts are here to help.
Troubleshooting Guide::
Symptom |
Solution |
Low capping efficiency or 2'-O-methylation efficiency |
RNA to be treated with ScriptCap™ Capping Enzyme should be purified and resuspended in RNase-free water. Do not resuspend the RNA in an EDTA-containing solution. |
Prior to capping, purify the input RNA using a method that removes residual proteins, contaminants and unincorporated nucleotides. |
Verify that ScriptGuard™ RNase Inhibitor was added to the reaction. |
SAM slowly degrades at room temperature and above. Keep SAM solutions on ice at all times. Be sure to use fresh dilutions of SAM which have always been stored on ice. Inefficient N7 methylation will result in inefficient capping. |
Increase the RNA heat-denaturation conditions used. For example, 65°C for 20 minutes, 75°C for 10 minutes, 85°C for 5 minutes, etc. |
Increase the capping reaction incubation time. For example, up to 3 hours at 37°C. |
Some RNAs form stable structures (e.g., homodimers, hairpins) at the 5' end, limiting access by Capping Enzyme. Analyze the sequence and increase the RNA denaturation temperature to above the Tm (e.g., to 65°C for 20 min, 75°C for 10 min, 85°C for 5 min). If the 5' end is highly structured, it might be necessary to modify the 5' end sequence using molecular biology techniques. Often this can be accomplished by making a single point mutation within the first 5 bases of the DNA template for the RNA transcript (non-coding region). |
White precipitate in reaction buffer |
Incubate the reaction buffer at 37°C for 5 minutes then mix thoroughly to dissolve the precipitate. |
Do not store the kit at –70°C. |
