RNeasy Universal Kits

For purification of total RNA from all types of tissue

Features

  • High yields of total RNA from all tissues
  • Fast non-enzymatic removal of genomic DNA
  • Streamlined QIAzol lysis and RNeasy 96 purification
  • Pure, high-quality RNA without phenol contamination
  • High-performance RNA for all downstream applications
RNeasy Plus Universal Mini Kit (50)

Cat. No. / ID: 73404

For 50 RNA minipreps: RNeasy Mini Spin Columns, gDNA Eliminator Solution, Collection Tubes, RNase-Free Water and Buffers
Column typePlate type
Mini
96 well

Product Details

The RNeasy Plus Universal Mini Kit integrates fast, convenient RNA purification with effective elimination of genomic DNA. Optimized protocols enable purification of high-quality RNA from any type of tissue, even difficult-to-lyse tissues. The kit includes QIAzol Lysis Reagent for lysing fatty tissue and other types of tissue and RNeasy spin columns for purifying high-quality RNA. The RNeasy Plus Universal Mini Kit can be automated on the QIAcube Connect.


The RNeasy 96 Universal Tissue Kit enables total RNA purification in 96-well format from any tissue. Tissues are efficiently lysed and homogenized in QIAzol Lysis Reagent, and high-quality RNA is purified using silica-membrane RNeasy 96 plates. Manual purification is carried out using the QIAGEN Centrifuge 4-16KS and, optionally, the QIAvac 96 vacuum manifold. Automated purification using the related RNeasy 96 Universal Tissue 8000 Kit is performed on the BioRobot Universal System. Tissue samples can be conveniently stabilized using Allprotect Tissue Reagent, and efficiently disrupted using the TissueLyser II. Nonfatty tissues can be stabilized using the RNAprotect Tissue Reagent.

Performance

The RNeasy Plus Universal procedure allows high, reproducible RNA yields from any type of tissue, including fatty tissues and difficult-to-lyse tissue (see table “Typical yields of total RNA using the RNeasy Plus Universal Mini Kit”). Yields can vary due to factors such as species and developmental stage, especially with adipose tissues.

Typical yields of total RNA with RNeasy Plus Universal Kits

Mouse/rat tissue (10 mg) Yield of total RNA ((µg)
Adipose tissue 0.5–2.5
Brain 5–20
Heart 5–25
Intestine 10–60
Kidney 5–40
Liver 15–80
Lung 5–15
Muscle 5–35
Skin 2–5
Spleen 15–100

Analysis of purified RNA by real-time RT-PCR, and on the QIAxcel system, demonstrates high-quality RNA with good integrity (see figure " High-quality RNA"). gDNA Eliminator Solution and RNeasy technologies efficiently remove most of the genomic DNA contamination without DNase treatment (see figure " Effective removal of genomic DNA").


Compared with standard silica-membrane procedures, the RNeasy 96 system provides higher yields of total RNA for all tissue types (see table “Typical total RNA yields using the RNeasy 96 Universal Tissue Kit”).

Typical total RNA yields using the RNeasy 96 Universal Tissue Kit

Tissue RNA yield* (µg per 10 mg of tissue)
Kidney 5–40
Liver 15–80
Lung 5–15
Heart 5–25
Muscle 5–35
Brain 5–20
Adipose tissue 0.5–2.5
Spleen 15–100
Intestine 10–60
Skin 2–5

High-quality RNA can be isolated from tissues preserved either by freezing or by stabilization with RNAprotect at room temperature (see figure "High-quality total RNA from rat liver and muscle tissue"). Intact RNA purified from difficult-to-lyse fibrous and fatty tissues is suitable for downstream applications (see figures " High-quality RNA from  skin /  adipose /  liver /  intestine tissue" and " Real-time analysis of high-quality RNA from rat brain").

See figures

Principle

The RNeasy Plus Universal Mini procedure enables purification of RNA from any type of tissue, including fatty or difficult-to-lyse tissues. The RNeasy Plus Universal Mini Kit integrates phenol/guanidine-based sample lysis and silica-membrane purification of total RNA. QIAzol Lysis Reagent, included in the kits, is a monophasic solution of phenol and guanidine thiocyanate, designed to facilitate lysis of all kinds of tissues and to inhibit RNases. The highly efficient lysis and the subsequent removal of contaminants by organic phase extraction enable the use of larger amounts of tissue with RNeasy spin columns. gDNA Eliminator solution effectively removes genomic DNA contamination and significantly improves separation of DNA into the interphase.


The RNeasy 96 Universal Tissue procedure enables high-throughput purification of RNA from any animal or human tissue sample. Compared with standard silica-membrane procedures, the RNeasy 96 Universal Tissue Kit provides higher yields of total RNA for all tissue types. The RNeasy procedure enriches for RNA >200 bases long, providing a yield of total RNA that does not include 5.8S rRNA, tRNA, and other low-molecular weight RNAs, which make up 15–20% of total cellular RNA.

Procedure

The RNeasy Plus Universal procedure is easy to follow and, compared to using phenol/chloroform to extract total RNA with a subsequent cleanup procedure, much faster and more efficient with better RNA purity and yield (see flowchart " RNeasy Plus Universal Mini procedure"). Total RNA is purified from up to 50 mg tissue using the RNeasy Plus Universal Mini Kit.


Tissue samples are homogenized in QIAzol Lysis Reagent using the TissueRuptor II, TissueLyser LT, or TissueLyser II. After addition of gDNA Eliminator Solution and chloroform, the homogenate is separated into aqueous and organic phases by centrifugation. The upper, aqueous phase with RNA is collected, mixed with ethanol, and RNA is purified using RNeasy spin columns. Total RNA binds to the spin column membrane, and phenol and other contaminants are efficiently washed away. High-quality RNA is eluted in RNase-free water.


The procedure provides an enrichment for mRNA since most RNAs <200 nucleotides (such as rRNAs and tRNAs) are excluded. The RNeasy Plus Universal procedure can be modified to allow the purification of total RNA containing small RNAs, such as miRNA, from cultured cells.


The optimized RNeasy 96 Universal Tissue procedure integrates TissueLyser / QIAzol processing with RNeasy 96 purification in an easy-to-follow protocol (see flowchart " RNeasy 96 Universal Tissue procedure"). Efficient high-throughput disruption using the TissueLyser II provides parallel disruption and homogenization, with lysis of up to 192 samples in QIAzol Lysis Reagent. Protocol steps are performed manually using the QIAGEN 96-Well-Plate Centrifugation System, with optional use of the QIAvac 96 vacuum manifold.

See figures

Applications

RNA purified using RNeasy Plus Universal Kits is ideally suited for downstream applications that are sensitive to low amounts of DNA contamination, such as RNA-seq, quantitative real-time RT-PCR. The purified RNA can also be used in other applications.


The combination of QIAzol and RNeasy technologies results in highly pure RNA without phenol carryover. RNA purified using the RNeasy 96 Universal Tissue Kit is suitable for all downstream applications, including RNA-seq, real-time RT-PCR and array analysis.

Comparison of RNeasy Universal Kits

Features RNeasy Plus Universal Mini Kit RNeasy 96 Universal Tissue Kit
Applications

Northern, dot, and slot blotting, end-point RT-PCR, quantitative,

real-time RT-PCR, array analysis, next-generation sequencing

PCR, qPCR, real-time PCR
Elution volume 30 µl; 45–70 µl
Format Mini 96-well plate
Integrated removal of genomic DNA Yes No
Main sample type Tissue samples including difficult-to-lyse and demanding tissues Tissue samples
Processing Manual (centrifugation), automated (QIAcube Connect) Manual (centrifugation or vacuum)

Purification of total RNA, miRNA,

poly A+ mRNA, DNA or protein

RNA RNA
Sample amount 5–50 mg 25–100 mg
Technology QIAzol/spin column technology Silica technology
Yield Varies Varies

Supporting data and figures

Resources

Kit Handbooks (2)
For high-throughput RNA purification from all types of animal tissue
For purification of total RNA from all types of tissue
Gene Expression Analysis (1)

FAQ

Is there also a miRNeasy Plus Universal Kit available?

No. The RNeasy Plus Universal Mini Kit contains a special protocol for micro RNA purification in the appendix.

 

 

FAQ ID -2346
For which applications can the RNA isolated with the RNeasy Plus Universal Kit also be used?
With the RNeasy Plus Universal Kit, high-quality total RNA is obtained and is well suited for all downstream applications.
FAQ ID -2339
Can I use the RNeasy Plus Universal Mini Kit for all types of tissue?
Yes. The RNeasy Plus Universal Mini Kit ensures that all types of tissue are rigorously lysed due to the use of phenol-guandine based QIAzol Lysis Reagent. QIAzol Lysis Reagent efficiently lyses all tissue types, allowing high yields of RNA.  Tissue samples can range from soft tissues to difficult-to-lyse materials.
FAQ ID -2338
I accidentally stored Buffer RDD of the RNase-Free DNase Set at°C. Will it still function?
Yes, buffer RDD of the RNase-Free DNase Set will still work. Please make sure that the buffer is thawed completely without any precipitates before using it. If precipitates are visible, the buffer should be slightly heated.
-20
Why are samples centrifuged at 4°C after addition of chloroform to the QIAzol lysates in following kits: RNeasy Lipid Tissue Mini/Midi kits, RNeasy Microarray Tissue Mini kit, RNeasy Plus Universal Mini/Midi kit, RNeasy 96 Universal Tissue kit, miRNeasy Mini kit, miRNeasy Micro kit, miRNeasy 96 kit and miRNeasy Serum/Plasma kit?
Phase separation by centrifugation at 4°C, after adding chloroform and gDNA Elimiator solution to the samples, minimizes genomic DNA contamination. Subsequent centrifugation steps with RNeasy spin columns have to be carried out at room temperature to prevent buffer salt precipitation and to guarantee optimal binding of RNA to the columns.  This then ensures the highest RNA yields possible.
FAQ ID -2345
Do you have a kit for RNA isolation from any kind of sample type?

The RNeasy 96 Universal Tissue Kit enables high-throughput purification of RNA from any animal or human tissue sample, including difficult-to-lyse fibrous and fatty tissues. For single tube format RNA purification, the RNeasy Plus Universal Kit is also available. 

Please refer to the Selection guide for RNA isolation for all sample types to find the optimal solution for your sample source.

FAQ ID -627
What is the composition of Buffer RLT?

The exact composition of Buffer RLT is confidential. This buffer is a proprietary component of RNeasy Kits. Buffer RLT contains a high concentration of guanidine isothiocycanate, which supports the binding of RNA to the silica membrane. Buffer RLT can be purchased separately (cat. no. 79216)

Note: note that ß-mercaptoethanol should be added to Buffer RLT before use to effectively inactivate RNAses in the lysate (10 µl ß-Mercaptoethanol per 1 ml Buffer RLT).

FAQ ID -2793
How can I avoid little or no RNA yields when using an RNeasy Kit?

Avoid RNA degradation due to improper sample storage and handling prior to the extraction procedure with RNeasy Kits. RNA in tissues is not protected after harvesting until the sample is treated with RNAprotect Tissue Reagent, flash frozen, or disrupted and homogenized in the presence of RNase-inhibiting or denaturing reagents. Samples can be immediately flash frozen in liquid nitrogen and stored at −90 to −65°C. as soon as they are harvested or excised. Frozen tissue should not be allowed to thaw during handling or weighing, but cell pellets can partially thaw enough to allow them to be dislodged by flicking. The relevant procedures should be carried out as quickly as possible. Samples can also be stored at −90 to −65°C. in lysis buffer (Buffer RLT) after disruption and homogenization. Frozen samples are stable for months.

For optimal RNA yields with RNeasy Kits it is crucial to:

  • Efficiently disrupt and homogenize the starting material.
  • Use the correct amount of starting material (do not overload!).
  • Perform all protocol steps at room temperature.
  • Perform the dry-spin prior to elution as described in the relevant protocol for a full 5 minutes.
  • Prepare the 80% ethanol for the wash steps with RNase-free water only.
  • Dispense the RNase-free water for elution onto the center of the membrane.
  • Optionally, repeat the elution step, and incubate the spin column on the bench for 10 minutes with RNase-free water before centrifuging.

Please review the instructions in the relevant RNeasy Handbook carefully for best results.


FAQ ID -28
Is the RNeasy Plus Universal Mini Kit suited for adipose, brain, and other fatty tissues?
Yes. The RNeasy Plus Universal Mini Kit is designed to extract RNA from various tissues, including more demanding materials such as adipose, brain, and other fatty tissues.
FAQ ID -2343
How can I check the integrity of RNA purified using RNeasy Kits?

The integrity and size distribution of total RNA purified with RNeasy Kits can be checked by denaturing-agarose gel electrophoresis, the Agilent 2100 bioanalyzer, or the QIAxcel Advanced System with the QIAxcel RNA QC Kit v2.0.

 

The respective ribosomal species should appear as sharp bands on the stained gel. 28S ribosomal RNA bands should be present with an intensity approximately twice that of the 18S RNA band. If the ribosomal bands are not sharp, but appear as a smear of smaller sized RNAs, it is likely that the RNA sample has suffered major degradation during preparation.

 

Size of ribosomal RNAs from various sources

 

Source rRNA Size (kb) E. coli 16S 1.5   23S 2.9 S. cerevisiae 18S 2.0   26S 3.8 Mouse 18S 1.9   28S 4.7 Human 18S 1.9   28S 5.0

 

 

 

 

 

 

 

 

 

FAQ ID -1024
I use cultured cells as starting material. Can I also use the RNeasy Plus Universal Kit?
Yes. Cultured cells can be processed using the RNeasy Plus Universal Mini Kit.  
FAQ ID -2342
What is the key technical challenge in isolating high quality RNA from cell or tissue samples?

Ribonucleases are the principal threat to any RNA isolation procedure. In addition, copurification of inhibitory contaminants is a major problem when isolating RNA from certain tissue sources. To minimize the threat, gloves should be worn at all times, and special care must be taken to use RNase-free reagents and labware.

In addition, tissue/cell lysis steps are typically carried out with lysis buffers containing guanidine isothiocyanate, a potent protein denaturant. It is very important to use a sufficient amount of lysis buffer during RNA isolation. We recommend using at least 10X volume of lysis buffer to tissue/cell pellet.

In general, for fast purification of high-quality RNA we recommend QIAGEN’s RNeasy Kits. It is more challenging to isolate high-quality RNA from tissue samples than from cultured cells, especially those tissues containing high levels of RNase, or difficult-to-homogenize tissues. Examples of such tissues include liver, heart, skin, and conjunctive tissues. Many tissue samples also contain difficult-to-remove contaminants (such as polysaccharides, collagen, fats, lipids or fibrous components) that may interfere with subsequent enzymatic reactions if not removed from the RNA preparation. For purification of high-quality RNA from difficult tissues we recommend QIAGEN’s RNeasy Plus Universal Kit.

FAQ ID -2656
How pure should the chloroform used with the RNeasy Plus Universal Mini Kit be?
In general, we recommend using Molecular Biology or higher grade chloroform, which should not contain isoamyl alcohol.
FAQ ID -2344
How can I check for purity of RNA isolated using RNeasy Kits?

Purity of RNA isolated with RNeasy Kits can be evaluated by determining the ratio of absorbance readings at 260 nm and 280 nm (A260/A280). This ratio provides an estimate of the purity of RNA with respect to contaminants that absorb in the UV range, such as protein.

Note that the A260/A280 ratio is influenced considerably by pH. As water is unbuffered, the pH and the resulting 260/280 ratio can vary greatly. For an accurate determination of purity, we recommend measuring the 260/280 absorbance in 10 mM Tris-Cl, pH 7.5. Be sure to calibrate the spectrophotometer with the same solution. Pure RNA has an A260/A280 ratio of 1.9-2.1. However, values up to 2.3 are routinely obtained for pure RNA (in 10 mM Tris, pH 7.5) with some spectrophotometers.

For details on how the pH influences nucleic acid purity measurements, please review the reference 'Effect of pH and ionic strength on the spectrophotometric assessment of nucleic acid purity', by Wilfinger WW, Mackey K, Chomczynski P, Biotechniques. 1997 Mar;22(3):474-6, 478-81.

FAQ ID -1023
I ran my RNA out on an agarose gel and can see lots of bands similar to a ladder. Why?

RNA has a high degree of secondary structure that needs to be resolved or denatured before running the sample out on a gel. A formaldehyde gel needs to be used to disrupt the secondary structure and eliminate a ladder effect. For details please refer to the chapter "A Guide to Analytical Gels" in the QIAGEN Bench Guide.

Some banding pattern may remain due to the presence of mRNA transcripts of different lengths specific for the respective cell or tissue type.

FAQ ID -745
How is the RNeasy Plus Universal Kit different from the RNeasy Plus Kit?

The RNeasy Plus Universal Mini Kit has been designed for optimal lysis of all types of tissue. Lysis and homogenization are performed using QIAzol Lysis Reagent, a phenol-guanidine based lysis reagent. The RNeasy Plus Mini Kit is the optimal solution for cells and easy-to-lyse tissue since lysis occurs with Buffer RLT. Additionally, the gDNA removal feature is based on a different technology. While the classic RNeasy Plus Kit contains gDNA eliminator columns, the RNeasy Plus Universal Kit contains a gDNA eliminator solution.

FAQ ID -2340
What is the composition of Buffer RWT?
The exact composition of Buffer RWT is confidential. Buffer RWT is a proprietary component of, for example, the miRNeasy Mini Kit and the RNeasy Plus Universal Kit. Guanidine salt and ethanol are important ingredients in Buffer RWT. Ethanol is added by the user prior to the first use of the kit. Buffer RWT is a stringent washing buffer used after preclearing the sample with QIAzol Lysis Reagent, especially if isolation of small RNAs, for example, microRNAs or RNAs from formalin-fixed tissue, is desired
FAQ ID -2798
What are the most reliable methods for preparing high-quality RNA from cell or tissue samples, for use in gene expression analysis experiments?
We recommend the use of RNeasy Mini Kits. Cultured cells, and freshly isolated white blood cells, may be harvested by centrifugation, and used directly with this kit. For the isolation of high-quality RNA from animal tissues, we recommend RNeasy Plus Universal Kit.
FAQ ID -2657
What is the difference between disruption and homogenization in the RNeasy System?

Disruption:

Complete disruption of cell walls and plasma membranes of cells and organelles is absolutely required to release all RNA contained in a sample. Different samples require different methods to achieve complete disruption. Please refer to the section 'Disruption and homogenization of starting materials' in the RNeasy Mini Handbook. Incomplete disruption results in significantly reduced RNA yields.

Homogenization:

Homogenization is necessary to reduce the viscosity of the cell lysates produced by disruption. Homogenization shears the high-molecular-weight genomic DNA and other high-molecular-weight cellular components to create a homogeneous lysate. Incomplete homogenization results in genomic DNA contamination, and inefficient binding of RNA to the RNeasy membrane resulting in reduced yields.

FAQ ID -139
Can the RNase-Free DNase Set be used for DNase digestions of RNA in solution?

Yes. Even though buffer RDD in the RNase-Free DNase Set is optimized for on-column DNase digestion, the buffer is also well-suited for efficient DNase digestion in solution. Please note that the reaction must be cleaned up after the off-column DNase digest to remove the enzyme and buffer RDD, which will interfere with subsequent RT reactions.

A protocol for in-solution DNase digestion using the RNase-Free DNase Set can be found in Appendix C of the RNeasy MinElute Cleanup Handbook. For subsequent RNA Cleanup, use either the RNeasy MinElute Cleanup Kit, or follow the instructions for RNA Cleanup in the RNeasy Mini Handbook.

 

FAQ ID -619
How should RNeasy Kits be stored and how long are they stable?
RNeasy Mini, Midi and Maxi Kits should be stored dry at room temperature (15 to 25°C). The RNeasy MinElute Spin Columns of the RNeasy Micro Kit and RNeasy MinElute Cleanup Kit should be stored at 4°C. RNeasy Kits are stable for at least 9 months under these conditions.
FAQ ID -103
What is the composition of gDNA Eliminator Solution?
The exact components of gDNA Eliminator solution are confidential as patents are still pending. gDNA Eliminator solution is a component of RNeasy Plus Universal Kits and is added prior to phase separation with QIAzol Lysis Reagent to further reduce gDNA contamination in the aqueous phase
FAQ ID -2799
What can be used as an alternative to the A260 measurement for quantification of small amounts of RNA and DNA?

Small amounts of RNA and DNA may be difficult to measure spectrophotometrically. Fluorometric measurements, or quantitative RT-PCR and PCR are more sensitive and accurate methods to quantify low amounts of RNA or DNA.

Fluorometric measurements are carried out using nucleic acid binding dyes, such as RiboGreen® RNA Quantitation Reagent for RNA, and PicoGreen® DNA Quantitation Reagent for DNA (Molecular Probes, Inc.).

FAQ ID -728
What is the composition of Buffer RLT plus?
In addition to all the components included in Buffer RLT, Buffer RLT Plus — a component of RNeasy Plus Kits — also contains a proprietary blend of detergents. These detergents support the efficient binding of DNA molecules to the gDNA Eliminator column or the gDNA Eliminator plate. The exact composition of Buffer RLT Plus is confidential. Buffer RLT Plus can be purchased separately (cat. no. 1053393).
FAQ ID -2794
How do you ensure that RNeasy buffers are RNase-free?

Our RNeasy buffers are subjected to stringent quality-control tests to ensure that they are indeed RNase-free. Buffer RPE concentrate and RNase-free water are tested for absence of RNases by incubating 4 µg of total HeLa-RNA in these solutions for 3 hours at 37°C, followed by monitoring RNA integrity via denaturing agarose gel electrophoresis and ethidium bromide staining.

Buffer RLT and Buffer RW1 are inherently RNase-free, since the buffers themselves inactivate RNases during the RNeasy procedure.

FAQ ID -113
Effects of low A260/A230 ratios in RNA preparations on downstream applications

The efficiency of downstream applications depends strongly on the purity of the RNA sample used.  Pure RNA should yield an A260/A230 ratio of around 2 or slightly above; however, there is no consensus on the acceptable lower limit of this ratio.  Possible candidates that can increase the A230 include “salt”, carbohydrates, peptides, and phenol (or aromatic compounds in general).  In our experience, the increased absorbance at 230 nm in RNA samples is almost always due to contamination with guanidine thiocyanate, present at very high concentrations in the lysis buffer or extraction reagent used in most RNA purification procedures.

Please find an article discussing the effect of low 260/230 ratios in RNA preparations on downstream applications on page 7 of QIAGEN Newsletter March 15, 2010 . In summary, we found that concentrations of guanidine thiocyanate of up to 100 mM in an RNA sample do not compromise the reliability of downstream applications.

 

 

FAQ ID -2248
What has to be done to an RNA sample before loading it onto an Agilent Bioanalyzer?

For RNA isolated on the BioRobot EZ1 and BioRobot M48:

The RNA can be directly applied to the Agilent Bioanalyzer, since it is being denatured in the final protocol steps of these isolation procedures.

For RNA prepared with all other QIAGEN RNA Isolation Products:

We recommend to denature the samples in a water bath for 2 min at 70°C, and then place them directly on ice prior to loading them onto the Agilent Bioanalyzer.

 

FAQ ID -528
Why does my isolated RNA have a low OD 260/280 ratio?

The A260/ A280 ratio is influenced considerably by pH. Since water is not buffered, the pH and the resulting A260/A280 ratio can vary greatly. Lower pH results in a lower A260/ A280 ratio and a reduced sensitivity to protein contamination*.

For accurate values, we recommend measuring absorbance in 10 mM Tris·Cl, pH 7.5. Always be sure to calibrate the spectrophotometer with the same solution. Please see the Appendix sections in the RNeasy handbooks for additional information.


* Wilfinger, W.W., Mackey, M., and Chomczynski, P. (1997) Effect of pH and ionic strength on the spectrophotometric assessment of nucleic acid purity. BioTechniques 22, 474.

FAQ ID -97
How do I safely inactivate biohazardous flow-through material?

Always dispose of potentially biohazardous solutions according to your institution’s waste-disposal guidelines. Although the lysis and binding buffers in QIAamp, DNeasy, and RNeasy kits contain chaotropic agents that can inactivate some biohazardous material, local regulations dictate the proper way to dispose of biohazards. DO NOT add bleach or acidic solutions directly to the sample-preparation waste. Guanidine hydrochloride in the sample-preparation waste can form highly reactive compounds when combined with bleach.
Please access our Material Safety Data Sheets (MSDS) online for detailed information on the reagents for each respective kit.

FAQ ID -12
What is the composition of Buffer RPE?
The exact composition of Buffer RPE is confidential. Buffer RPE is a mild washing buffer, and a proprietary component of RNeasy Kits. Its main function is to remove traces of salts, which are still on the column due to buffers used earlier in the protocol. Ethanol, which is added by the user just before using the kit for the first time, is an important ingredient of Buffer RPE.
FAQ ID -2797
How does the gDNA eliminator solution of the RNeasy Plus Universal Kit work?
The gDNA eliminator solution is a novel non-enzymatic solution, which reduces gDNA contamination of the aqueous phase.  It does not contain DNase. 
FAQ ID -2341
What is the composition of Buffer RW1?

The exact composition of Buffer RW1 is confidential. Buffer RW1 is a proprietary component of RNeasy Kits. Buffer RW1 contains a guanidine salt, as well as ethanol, and is used as a stringent washing buffer that efficiently removes biomolecules such as carbohydrates, proteins, fatty acids etc., that are non-specifically bound to the silica membrane. At the same time, RNA molecules larger than 200 bases remain bound to the column.

Note: Buffer RW1 should not be used for isolation of small RNAs, for example, microRNAs or fragmented RNA from formalin-fixed tissues, as these smaller fragments will be washed away.  Buffer RWT should be used instead.

FAQ ID -2796
How should I quantify RNA isolated with RNeasy Kits?

The concentration of RNA isolated with RNeasy Kits can be determined by measuring the absorbance at 260 nm (A260) in a spectrophotometer. Absorbance readings should be greater than 0.15 to ensure significance. An absorbance of 1 unit at 260 nm corresponds to 40 µg of RNA per ml (A260 = 1 = 40 µg/ml). This relationship is valid for measurements in water. Therefore, dilute RNA in water to quantify it spectrophotometrically.

An example of the calculations involved in RNA quantification is shown below. Use the buffer in which the RNA is diluted to zero the spectrophotometer:

  • Volume of RNA sample = 100 µl
  • Dilution = 10 µl of RNA sample + 490 µl distilled water (1/50 dilution)
  • Absorbance of diluted sample measured in a 1 ml cuvette (RNase-free): A260 = 0.23
  • Concentration of original RNA sample = 40 x A260 x dilution factor = 40 x 0.23 x 50
  • RNA concentration: 460 µg/ml

  • Total yield = concentration x volume of sample (ml) = 460 µg/ml x 0.1 ml
  • RNA yield: 46 µg

For additional information on RNA quantitation and handling, see the Appendix section in the RNeasy Mini Handbook.

FAQ ID -32
Can I buy the gDNA eliminator columns supplied in your RNeasy Plus kits separately?

We do not sell the gDNA eliminator columns separately.

FAQ ID - 3390