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View additional product information for SuperScript™ III Reverse Transcriptase - FAQs (18080093, 18080044, 18080085)
21 product FAQs found
旧バージョンのソフトウェアでは、Relative Quantification Plate(⊿⊿Ct）アッセイを行う場合、同一ファイル中に融解曲線を設定することができません。ただし最近の機種や、7500/7500fastの最新のsofware( ver.2.0.5)では、サイクルステージの直後にmelt curve(融解曲線）が設定可能となっています。 なお旧バージョンのソフトウェアの場合は、Relative Quantification Plate(⊿⊿Ct）アッセイを行った後に、新しいRunファイルを作成し、融解曲線のみのプログラムでRunを行ってください。 融解曲線のみのRunを行う場合、"File"から "New"を選択します。展開された" New Document Wizard"画面中の"Assay"のプルダウンメニューから"DISSOCIATION"を選択し、融解曲線のみのRunを行ってください。この場合、解析ファイルとは別に融解曲線のみのSDSファイルが作成されます。
The following components are available as stand-alone items:
- Superscript III Reverse Transcriptase (Cat. Nos. 18080093, 18080044, 18080085)
- Oligo (dT)20 Primer (Cat. No. 18418020)
- Random hexamers (Cat. No. 48190011)
- 10 mM dNTP Mix (Cat. Nos. 18427013, 18427088)
- RNAseOUT Recombinant Ribonuclease Inhibitor (Cat. No. 10777019)
- E. coli RNAse H (Cat. Nos. 18021014, 18021071)
SuperScript III Reverse Transcriptase (Cat. Nos. 18080093, 18080044, 18080085) contains the stand-alone enzyme and a vial each of 5X first-strand buffer and 100 mM DTT.
SuperScript III First Strand Synthesis System for RT-PCR is a complete kit that provides the SuperScript III Reverse Transcriptase and all the other components required for synthesis of first-strand cDNA from total or poly(A)- RNA. It includes:
- Superscript III Reverse Transcriptase
- Oligo (dT)20 Primer
- Random hexamers
- 10X RT buffer
- 25 mM MgCl2
- 0.1 M DTT
- 10 mM dNTP Mix
- RNAseOUT Recombinant Ribonuclease Inhibitor
- E. coli RNAse H
- DEPC-treated water
- Total HeLa RNA control
- Sense control primer
- Anti-sense control primer
Note: The kit does not include the PCR amplification enzyme.
If amplification products are generated in the control tube/well that contains no reverse transcriptase (i.e., the no-RT control), it may be necessary to eliminate residual genomic DNA from the RNA sample. Use the following protocol to remove genomic DNA from the total RNA preparation.Random primers are the best choice for degraded RNA, RNA with heavy secondary structure, non-polyadenylated RNA, or prokaryotic RNA. It is recommended only for two-step RT-PCR, and typically gives the highest yields, although the cDNA may not necessarily be full length. Oligo(dT) primers are good to use when trying to recover full-length cDNA from 2-step RT-PCR. The reaction is influenced by secondary structure and RNA quality. Gene specific primers should be used for very specific, mainly one-step RT-PCR reactions.
Random primers are the best choice for degraded RNA, RNA with heavy secondary structure, non-polyadenylated RNA, or prokaryotic RNA. It is recommended only for two-step RT-PCR, and typically gives the highest yields, although the cDNA may not necessarily be full length. Oligo(dT) primers are good to use when trying to recover full-length cDNA from 2-step RT-PCR. The reaction is influenced by secondary structure and RNA quality. Gene specific primers should be used for very specific, mainly one-step RT-PCR reactions.
Add the following to an autoclaved 0.5 mL microcentrifuge tube on ice:
1.Total RNA, ideally, less than or equal to 1 µg. (See Note 1 below.)
2.1.0 µL of 10X DNase buffer (200 mM Tris, pH 8.3, 500 mM KCl, 20 mM MgCl2).
3.0.1 U-3.0 U of DNase I (RNase-free, Cat. No. 18047019) or 1.0 U Dnase I, Amplification Grade (Cat. No. 18068015. (See Note 2 below.)
4.Bring volume up to 10 µL with DEPC-treated water.
5.Incubate at room temperature for 15 min. (See Note 3 below.)
6.Terminate the reaction by adding 1 µL 25 mM EDTA and heat 10 min at 65 degrees C. (See Note 4 below.)
7.Place on ice for 1 minute.
8.Collect by brief centrifugation. This mixture can be used directly for reverse transcription.
Please note the following:
1.To work with higher quantities of RNA, scale up the entire reaction linearly. Do not exceed 2 µg RNA in the 10 µL reaction. More RNA will increase the viscosity of the solution and prevent the DNAse I from diffusing and finding the DNA.
2.DNAse I, Amplification Grade has been extensively purified to remove trace ribonuclease activities commonly associated with other "RNAse-free" enzyme preparations and does not require the addition of placental RNAse inhibitor.
3.It is important not to exceed the 15 minute incubation time or the room temperature incubation. Higher temperatures and longer times could lead to Mg2+-dependent hydrolysis of the RNA.
4.This procedure requires careful pipetting of all solutions so that the concentration of divalent metal cation (Mg2+) is controlled.
5.Because the DNAse I must be heated to 65 degrees C to inactivate the enzyme, the concentration of free divalent metal ions must be low enough (less than 1 mM) after addition of the EDTA to prevent chemical hydrolysis of the RNA. See references below.
After the addition of EDTA, there is an approximately 1:1 molar ratio of Mg2+ :EDTA. EDTA chelates Mg2+ molecules on a 1:1 molar basis. Therefore, this RNA can be directly used in a reverse transcription reaction. First-strand reverse transcription buffers typically result in a final concentration of 2.5 mM Mg2+. If the reverse transcription buffer does not contain MgCl2, add it to the reaction at a final concentration of 2.5 mM. This results in a net final concentration of approximately 2.25 to 2.5 mM MgCl2.
References on RNA hydrolysis:
Molekulyarnaya Biologiya (1987) 21:1235-1241.
References on the mechanism of hydrolysis by other cations:
Eichorn GL and Butzov JY (1965) Biopolymers 3:79.
Butzov JY and Eichorn GL (1965) Biopolymers 3:95.
Farkas WR (1968) Biochim Biophys Acta 155:401.
The authors of the first paper express the opinion that the mechanism of the nonspecific hydrolysis by cations which proceeds through 2',3' cyclic phosphate formation is similar to that of specific hydrolysis such as RNA splicing.
The amount of RNA template for a cDNA synthesis is highly flexible and depends upon the amount of sample available and an individual's need. In general, 1 µg total RNA is used in a typical 20-µL RT reaction.
Find additional tips, troubleshooting help, and resources within ourReverse Transcription and RACE Support Center.
Some feel that the RNA in the RNA:DNA duplex after reverse transcription will inhibit PCR primers from annealing and amplifying the cDNA. The RNA is still present when using RNase H-mutant RTs. RNase H frees the cDNA from the RNA. On the other hand, some feel that the 95 degrees C denaturing step will cause the RNA primers to fall off the DNA and therefore RNase H treatment is not necessary. Therefore, this step is optional. For cloning of larger fragments, RNase H treatment can be beneficial.
This depends highly on the quality of the sample. mRNA itself makes up 1-5% of total RNA. Depending on the primer and enzyme used, reverse transcription can covert >70% of that into cDNA.
Find additional tips, troubleshooting help, and resources within our Reverse Transcription and RACE Support Center.
Random primers are the best choice for degraded RNA, RNA with heavy secondary structure, non-polyadenylated RNA, or prokaryotic RNA. It is recommended only for two-step RT-PCR, and typically gives the highest yields, although the cDNA may not necessarily be full length. Oligo(dT) primers are good to use when trying to recover full-length cDNA from 2-step RT-PCR. The reaction is influenced by secondary structure and RNA quality. Gene specific primers should be used for very specific, mainly one-step RT-PCR reactions.
Find additional tips, troubleshooting help, and resources within our Reverse Transcription and RACE Support Center.
No, the DTT will need to be replaced.
These enzymes contain the domains of RNase H, but they have been mutated. In RNase H activity detection assays, we are not able to detect any RNase H activity.
Yes, we sell a M-MLV RT buffer (Cat. No. 18057018), which works with M-MLV RT, SuperScript II RT, and SuperScript III RT.
No. After the addition of EDTA, there is an approximately 1:1 molar ratio of Mg2+:EDTA. EDTA chelates Mg2+ molecules on a 1:1 molar basis. Therefore, this RNA can be directly used in a reverse transcription reaction. First-strand reverse transcription buffers typically result in a final concentration of 2.5 mM Mg2+. If the reverse transcription buffer does not contain MgCl2, add it to the reaction at a final concentration of 2.5 mM. This results in a net final concentration of approximately 2.25 to 2.5 mM MgCl2.
It is recommended to use the buffer that comes supplied with the enzyme. The reasons for the slight differences are that the kits were developed at different times, possibly by different R&D groups.
No, if TdT activity is required please use our SuperScript II RT.
The SuperScript VILO cDNA Synthesis Kit contains a mix of SuperScript III RT and helper proteins which help to increase the efficiency of the reverse transcription reaction and thus improve yield. The RT in the SuperScript
The SuperScript VILO cDNA Synthesis Kit (Cat. No. 11754050) contains a mix of SuperScript III RT and helper proteins which help to increase the efficiency of the reverse transcription reaction and thus improve yield. The RT in the SuperScript VILO kit is active at 42 degrees C due to the helper proteins.
While the volume is dependent on the starting amount of RNA used for the first-strand synthesis and the abundance of the target gene, we'd recommend starting with 10% of the first-strand reaction for your PCR reaction.
A low number of cDNA clones could result due to the reasons listed below:
(1) Phenol extractions were performed with phenol that was equilibrated with water that was not DEPC-treated.
(2) Poor first strand yield.
(3) No RNase H was added to second-strand reaction.
(4) Second-strand reaction was performed at a temperature greater than 16 degrees C.
(5) Dilution of first-strand reaction was made incorrectly: exact dilution is crucial, because the pH of the second-strand reaction differs from that of the first-strand reaction.
(6) The size fractionation column ran too quickly, the column was allowed to dry before fractions were loaded, or the column was not washed thoroughly to remove ethanol.
(7) Competent cells were of poor efficiency: verify efficiency of transformation with a control DNA.
(8) There was an insufficient amount of cDNA in the ligation mix.
(9) If cells were transformed by electroporation, there may have been too much salt in the electroporation mix, which kills cells.
Please see listed below a few reasons why you may be getting small first-strand cDNA products:
(1) Template was degraded by RNase contamination: maintain aseptic conditions.
(2) Secondary structure is present in the RNA:
-Heat the RNA to 70 degrees C for 10 min and quick-chill on ice to denature the RNA. Increase the temperature of the first strand reaction up to 50 degrees C. Denature the RNA by treatment with 20 mM methylmercuric hydroxide (see Krug et. al. (1987) Methods Enzymol 152:316).
-Try alternate reverse transcriptase such as SuperScript III polymerase and perform first-strand synthesis at higher temperature.
(3) Alkaline gel electrophoresis was performed incorrectly: use a 1% alkaline agarose gel.
(4) For random-primed first-strand cDNA, an excessive concentration of primers was used: use 50 ng random hexamers/1-5 µg total RNA.
(4) Incorrect fractions were taken at the column chromatography step.
The enzymes can be inactivated by adding a chelating agent such as EDTA. Alternatively, with the exception of ThermoScript RT and Thermo-X RT, the enzymes can be heat inactivated at 70 degrees C for 10 min.
ThermoScript RT should be heated to 85 degrees C for 5 min for complete inactivation.
For Thermo-X RT, if using an oligo(dT) primer, add EDTA to the reaction at a final concentration of 5 mM. Inactivate the reaction by heating at 90 degrees C for 5 min.
Yes, you can use a DNA-RNA hybrid as a template for M-MLV Reverse Transcriptase.
We have not tested this for SuperScript reverse transcriptases, so we cannot guarantee it would also work with those products.
This article can be used as a reference for additional information.
Find additional tips, troubleshooting help, and resources within our Reverse Transcription and RACE Support Center.
You can store the cDNA at -20 degrees C for up to 1 week. For long-term storage, we recommend storing the cDNA at -70 degrees C.