FastGene Scriptase II

Affordable Reverse Transcriptase in a 4-Step, Ready-Mix Format

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A reverse transcriptase engineered to deliver phenomenal results
What if a reverse transcriptases was constructed to synthesize very long cDNAs from very low amounts of input RNA in a very short time? That is the exact case for FastGene Scriptase II. To achieve this feat, first, mutations are inserted into the RNase H domain of native MuLV‘s reverse transcriptase delivering a higher yield of full-length cDNA.  Next changes are made to increase the enzymes natural thermal stability providing a more robust enzyme that doesn’t lose processing power, even at elevated temperatures. In addition, the reaction buffer composition is optimized for high speed production of cDNAs from incredibly low levels of input RNA. This unique combination of size, speed, and production makes FastGene Scriptase II  the optimal choice for even the most complex applications requiring cDNAs, such as RT-qPCR and NGS. Here is some !


  • Quantification of Gene Expression
  • RT-qPCR
  • Next Generation Sequencing
  • Low RNA concentration
  • Difficult templates

Longer cDNAs in less time
The FastGene Scriptase II has a modified RNase H domain which reduces the active lysis of the template RNA. By slowing this degradation the template remains intact for just long enough to deliver cDNAs of greater length. It is common to achieve cDNA size of up to 12 kBp. The quality of this engineered is so good that typical incubation times of 50 mins can be reduced to as little as 5 minutes.

The ReadyMix format makes it soooo easy!
FastGene Scriptase II comes in three convenient formats. You can just purchase the Scriptase II reverse transcriptase with the bare essentials, 5x RT buffer, dNTPs, DTT and some RNAse-free water (LS53). You can purchase the complete cDNA synthesis (LS63) that contains everything in the LS53 format plus anything else you need for optimizing the perfect cDNA synthesis blend for your particular application (e.g. random hexamer primers, oligo dT primers, and RNase inhibitor). The last option is the ReadyMix format (LS64) , and this is for those labs that need results quickly and without the need to optimize.

Expect great results from mulit-plex PCR, qPCR, and NGS
The FastGene Scriptase II delivers superior cDNA templates for downstream applications for common applications such as PCR, qPCR, and NGS. The resulting full-length cDNA is of the highest quality and gives a complete picture of the gene and any modification, e.g. splicing variants. Results using Scriptase II compare very favorably to the most popular brands of reverse transcriptases. For example, complicated multi-plex PCR reactions using cDNA derived from Scriptase II are indistinguishable between brands. In these examples below, GAPDH and YWHAZ were carefully examined via qPCR and both show nearly identical Ct values across a broad range of input RNA concentrations.

Comparison of qPCR results using primers for GAPDH and cDNA produced by using different RNA starting concentration by Competitor I‘s SS-II enzyme   and FastGene Scriptase II at 42 °C.


Comparison of qPCR results using primers for YWHAZ and cDNA produced by using different RNA starting concentration by Competitor I‘s SS-II enzyme and FastGene Scriptase II at 42 °C.

Comparison of different PCR results — multiplex PCR
Comparison of multiplex PCR using cDNA produced by Competitor I‘s SS-II enzyme and FastGene Scriptase II at 42 °C and 50 °C.

Additional Information

FastGene Scriptase II has been used by researchers in Europe and Japan since 2017. Here are couple opinions that exemplify how labs are responding to this new reverse transcriptase.

Kinki University, Osaka, Japan on 07/12/2018

I especially like that the Scriptase II lead to stable results. As a result of performing RT-PCR using tumor derived RNA, we were able to detect the expression of genes whose amplification was unstable with other RT reagents. The Amplification of full-length cDNA has also been confirmed. I would love to also try the 5x Ready Mix.

GIGA Cancer, Liège, Belgium on 09/27/2017

We have tested the RT kit FastGene Scriptase II in comparison with other kits, like Protoscript II (NEB) and Superscipt II (Invitrogen) and we have noted that the results are similar. Additionally, we can make more “runs” for a better price!

LS53 LS63 LS64
# of Reactions 100 100 100
Kit Contents – FastGene Scriptase II (20,000 U)
– 5x FastGene RT buffer
– DTT (0.1 M)
– dNTP Mixture (2mM each)
– FastGene Scriptase II (200 U/µl)
– 5x FastGene RT buffer
– dNTP Mixture (2mM each)
– Sterile water (RNase free)
– RNase Inhibitor (40 U/µl)
– Oligo dT Primer (80 µM)
– Random hexamer (100 µM)
– FastGene Scriptase II (200 U/µl)
– 5x FastGene RT buffer
– dNTP Mixture (2mM each)
– RNase Inhibitor (40 U/µl)
– Random hexamer (100 µM)
– Helper Protein
Concentration of template RNA
• Total RNA: 1 ng-5 µg
• Messenger RNA (mRNA): 1 ng-0.25 µg
• Specific RNA: 0.01 pg-0.5 µg
cDNA length up to 12kb
RNase-free Yes
Inhibitor-free Yes
Exonuclease-free Yes
Endonuclease-free Yes
Purity >99% on SDS-PAGE
Storage 1 year at -20°C