Product Class: Other

Hi-T7™ RNA Polymerase
icon_recomb engineered icon_NEBU incubation temp
Item# Description List Price Web Price Qty
M0658S Hi-T7 RNA Polymerase - 5,000 units $118.00
*On-line ordering is for Canadian customers only. Web pricing is applicable only to orders placed online at

    Product Introduction

    Hi-T7 RNA Polymerase is designed for in vitro transcription of RNA at higher temperatures.

    • Supplied with 10X Hi-T7 RNA Polymerase Reaction Buffer formulated for optimal performance
    • Active from 37-56°C
    • For standard in vitro transcription at 37°C use T7 RNA Polymerase (NEB# M0251)
    • Increased co-transcriptional capping efficiency with cap analogs
    • Decreased immunogenicity from RNA synthesized at higher temperature due to reduced dsRNA by-product formation
    • Interested in formulations for high-yield reactions? Contact us at [email protected]

    Product Information


    Hi-T7 RNA Polymerase is an engineered DNA-dependent RNA polymerase that is highly specific for T7 phage promoters and is designed to function at higher temperatures than the wild-type bacteriophage T7 RNA Polymerase. Hi-T7 RNA Polymerase functions at an optimal temperature of 50-52°C.

    Hi-T7 RNA Polymerase reduces dsRNA by-products at higher IVT reaction temperatures

    Immunoblot using an anti-dsRNA antibody (J2) shows presence of dsRNA by-products in the IVT reactions for both T7 and Hi-T7 RNA Polymerases when IVT is performed at 37°c. HPLC purification of the IVT RNA eliminates dsRNA by-products. dsRNA by-products are reduced when IVT is performed at 50°c (or higher temperatures) with Hi-T7.

    Product Source

    An E. coli strain that carries a plasmid encoding the engineered T7 RNA Polymerase gene.

    Reagents Supplied

    The following reagents are supplied with this product:

    Store at (°C) Concentration
    Hi-T7™ RNA Polymerase Reaction Buffer -20 10X
    Product Categories:
    RNA Modification Products,
    RNA Synthesis Products
    RNA Analysis,
    In vitro Synthesis (IVT)

    Advantages and Features

    Application Features

    • Radiolabeled RNA probes
    • Non-isotopic RNA labeling
    • Guide RNA for gene targeting
    • mRNA for in vitro translation, microinjection and transfection 
    • RNA structure, processing and catalysis studies
    • RNA amplification
    • Isothermal amplification
    • Anti-sense RNA for gene expression

    Properties & Usage

      Unit Definition

      One unit is defined as the amount of enzyme required to incorporate 1 nmol of ATP into acid-insoluble material in 1 hour at 50°C.

      Reaction Conditions
      1X Hi-T7 RNA Polymerase Reaction Buffer, supplemented with 0.5 mM each of ATP, UTP, GTP, CTP, and DNA template containing the T7 RNA Polymerase promoter.  Incubate at 37-56°C for 1 hour.  Optimal incubation temperature is 50-52°C.

      Reaction Conditions

      1X Hi-T7™ RNA Polymerase Reaction Buffer
      Supplement with 0.5 mM GTP, 0.5 mM ATP , 0.5 mM UTP  and 0.5 mM CTP 
      Incubate at 50°C

      1X Hi-T7™ RNA Polymerase Reaction Buffer
      40 mM Tris-HCl
      4 mM MgCl2
      50 mM NaCl
      2 mM spermidine
      1 mM DTT
      (pH 7.5 @ 25°C)

      Storage Temperature


      Storage Conditions

      50 mM Tris-HCl
      100 mM NaCl
      1 mM EDTA
      1 mM DTT
      0.1% Triton® X-100
      50% Glycerol
      pH 7.9 @ 25°C

      Unit Assay Conditions

      1X Hi-T7 RNA Polymerase Reaction Buffer, supplemented with 0.5 mM each ATP, UTP, GTP, CTP and 1 µg T7 phage DNA in 50 µl reaction volume.

      Protocols, Manuals & Usage


      1. Protocol for Standard RNA Synthesis with Hi-T7 RNA Polymerase (NEB #M0658)

      Faqs & Troubleshooting


      1. Can I use a different reaction buffer for in vitro transcription with Hi-T7 RNA Polymerase?
      2. Does Hi-T7 RNA Polymerase recognize the same promoter sequence as the wild-type T7 RNA Polymerase from bacteriophage?
      3. At what temperature is Hi-T7 RNA Polymerase active?
      4. What are the main causes of reaction failure when using Hi-T7 RNA Polymerase?
      5. What templates can be used for in vitro transcription with Hi-T7 RNA Polymerase?
      6. Can Hi-T7 RNA Polymerase transcribe off of an uncut plasmid?


      Quality, Safety & Legal

      Quality Assurance Statement

      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.


      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 DataSheets

      The following is a list of Safety Data Sheet (SDS) that apply to this product to help you use it safely.

      Legal and Disclaimers

      This product is covered by one or more patents, trademarks and/or copyrights owned or controlled by New England Biolabs, Inc (NEB).

      While NEB develops and validates its products for various applications, the use of this product may require the buyer to obtain additional third party intellectual property rights for certain applications.

      For more information about commercial rights, please contact NEB's Global Business Development team at [email protected].

      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.