WarmStart® RTx Reverse Transcriptase

Catalog #	Concentration	Size	List Price	Quantity	Your Price
M0380L	15000 units/ml	2000 units	$450.00		$405.00
M0380S	15000 units/ml	400 units	$113.00		$101.70

Catalog #	Size	List Price	Your Price
M0380L	2000 units	$450.00	$405.00
M0380S	400 units	$113.00	$101.70

WarmStart RTx Reverse Transcriptase is a unique in silico designed RNA-directed DNA polymerase coupled with a reversibly-bound aptamer that inhibits RTx activity below 40°C. This enzyme can synthesize a complementary DNA strand initiating from a primer using RNA (cDNA synthesis) or single-stranded DNA as a template. RTx is a robust enzyme for RNA detection in amplification reactions and is particularly well suited for use in LAMP (loop-mediated isothermal amplification). The WarmStart property enables high throughput applications, room temperature setup, and increases the consistency and specificity of amplification reactions. RTx contains intact RNase H activity.

To support lyophilization, incorporation into microfluidic devices, and enable quick adoption into automation workflows, WarmStart RTx Reverse Transcriptase is also offered in a glycerol-free format.

Improved Speed and Sensitivity in RT-LAMP — RT-LAMP reactions with Bst 2.0 WarmStart DNA Polymerase and the indicated reverse transcriptase were incubated at 65°C with 1 pg - 100 ng of Jurkat total RNA. Reactions were monitored with real-time fluorescence, and the resulting curves are shown on left, with the corresponding threshold times on right. WarmStart RTx provides faster reaction threshold times for improved consistancy and sensitivity with lower input RNA amounts. RT-LAMP reactions performed with AMV Reverse Transcriptase resulted in inconsistent detection, as indicated by wide variation at lower RNA input concentrations (blue curves).

Sensitive Detection with Reduced False Negatives

Total RNA	WarmStart RTx	AMV RT
100 ng	3/3	3/3
10 ng	3/3	3/3
1 ng	3/3	3/3
100 pg	3/3	2/3
10 pg	3/3	2/3
1pg	3/3	1/3

RT-LAMP reactions were performed with WarmStart RTx and AMV Reverse Transcriptase with total RNA at 6 input concentrations. Positive detection, indicated by fluorescent detection with a twenty-minute reaction time, was achieved down to 1 pg of total input RNA. Use of AMV resulted in false negatives when total RNA was 100 pg or lower.

WarmStart Control of WarmStart RTx — cDNA synthesis was performed for 10 minutes followed by qPCR analysis. Resulting Cts were normalized against both a "no RT" control for 0% activity and the fastest Ct for 100% activity. WarmStart RTx is inhibited by a reversibly-bound aptamer at temperatures below 40°C.

Robust RT-LAMP Across a Range of Targets — A variety of RT-LAMP targets were amplified using Bst 2.0 WarmStart^® DNA Polymerase and the indicated reverse transcriptase. Reactions with WarmStart RTx resulted in faster threshold times and more consistent reaction success across a range of targets and copy number.

Reagents Supplied

The following reagents are supplied with this product:

NEB #

Component Name

Component #

Stored at (°C)

Amount

Concentration

M0380S -20

WarmStart^® RTx Reverse Transcriptase	M0380SVIAL	-20	1 x 0.027 ml	15,000 units/ml
Isothermal Amplification Buffer Pack	B0537SVIAL	-20	1 x 1.5 ml	10 X
Magnesium Sulfate (MgSO₄) Solution	B1003SVIAL	-20	1 x 1.5 ml	100 mM

M0380L -20

WarmStart^® RTx Reverse Transcriptase	M0380LVIAL	-20	1 x 0.134 ml	15,000 units/ml
Isothermal Amplification Buffer Pack	B0537SVIAL	-20	1 x 1.5 ml	10 X
Magnesium Sulfate (MgSO₄) Solution	B1003SVIAL	-20	1 x 1.5 ml	100 mM

Application Features

RT-LAMP
cDNA synthesis
RT reactions requiring room temperature setup

Properties & Usage

Unit Definition

One unit is defined as the amount of enzyme that will incorporate 1 nmol of dTTP into acid-insoluble material in a total reaction volume of 50 μl in 20 minutes at 50°C using poly(rA)•oligo(dT)18 as template.

Reaction Conditions

1X Isothermal Amplification Buffer Pack

1X Isothermal Amplification Buffer Pack
20 mM Tris-HCl
10 mM (NH₄)₂SO₄
50 mM KCl
2 mM MgSO₄
0.1% TweenÂ® 20
(pH 8.8 @ 25°C)

Storage Buffer

100 mM KCl
10 mM Tris-HCl
0.1 mM EDTA
1 mM DTT
50% Glycerol
pH 7.4 @ 25°C

Heat Inactivation

80°C for 10 minutes

Unit Assay Conditions

20 mM Tris-HCl (pH 8.8), 10 mM (NH₄)₂SO₄, 50 mM KCl, 2 mM MgSO₄, 0.1% Tween-20, 0.5 mM dTTP, 0.4 mM poly(rA)•oligo(dT)18.

Companion Products

Notes

Reaction Conditions: 1X Isothermal Amplification Buffer, template, primer, dNTPs and 0.25–0.5 µl of WarmStart RTx Reverse Transcriptase in a reaction volume of 25 µl. Incubate at 50–55°C for cDNA synthesis or directly at 65°C for One-step RT-LAMP.

Protocols

Web Tools

NEB LAMP Primer Design Tool

FAQs

Citations

See more details on Bioz

Quality Control Assay

Quality Control tests are performed on each new lot of NEB product to meet the specifications designated for it. Specifications and individual lot data from the tests that are performed for this particular product can be found and downloaded on the Product Specification Sheet, Certificate of Analysis, data card or product manual. Further information regarding NEB product quality can be found here.

Change Notifications

To standardize product size and provide flexibility to usage, effective April 2, 2024, this product is now sold in terms of Units. This will result in the following changes:

M0380S: 50 Reactions changed to 400 Units
M0380L: 250 Reactions changed to 2,000 Units

Specifications

The Specification sheet is a document that includes the storage temperature, shelf life and the specifications designated for the product. The following file naming structure is used to name these document files: [Product Number]_[Size]_[Version]

Certificate of Analysis

The Certificate of Analysis (COA) is a signed document that includes the storage temperature, expiration date and quality controls for an individual lot. The following file naming structure is used to name these document files: [Product Number]_[Size]_[Version]_[Lot Number]

Safety Data Sheets

Legal And Disclaimer

Products and content are covered by one or more patents, trademarks and/or copyrights owned or controlled by New England Biolabs, Inc (NEB). The use of trademark symbols does not necessarily indicate that the name is trademarked in the country where it is being read; it indicates where the content was originally developed. The use of this product may require the buyer to obtain additional third-party intellectual property rights for certain applications. For more information, please email busdev@neb.com.

This product is intended for research purposes only. This product is not intended to be used for therapeutic or diagnostic purposes in humans or animals.

New England Biolabs (NEB) is committed to practicing ethical science – we believe it is our job as researchers to ask the important questions that when answered will help preserve our quality of life and the world that we live in. However, this research should always be done in safe and ethical manner. Learn more.Nucleic acid-based aptamers for use with reverse transcriptases are licensed exclusively by New England Biolabs, Inc. from SomaLogic, Inc. New England Biolabs, Inc. gives the Buyer/User a non-exclusive license to use the WarmStart® RTx Reverse Transcriptase for Research Use Only (RUO). Commercial use of this product may require a license from New England Biolabs, Inc. For additional information or to inquire about commercial use, please contact busdev@neb.com.