RNeasy MinElute Cleanup Kit

For RNA cleanup and concentration with small elution volumes

Features

  • Efficient cleanup of enzymatic reactions
  • Concentration of small amounts of RNA to only 10 µl
  • Cleanup of RNA purified by different methods
  • High-quality RNA in less than 15 minutes
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RNeasy MinElute Cleanup Kit (50)

Cat. No. / ID: 74204

50 RNeasy MinElute Spin Columns, Collection Tubes (1.5 ml and 2 ml), RNase-free Reagents and Buffers
NOK 3,485.00
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The RNeasy MinElute Cleanup Kit is intended for molecular biology applications. This product is not intended for the diagnosis, prevention, or treatment of a disease.

✓ 24/7 automatic processing of online orders

✓ Knowledgeable and professional Product & Technical Support

✓ Fast and reliable (re)-ordering

Product Details

The RNeasy MinElute Cleanup Kit enables cleanup and concentration of RNA from enzymatic reactions or other samples using specialized RNeasy MinElute spin columns based on silica-membrane technology. The kit can also be used to desalt RNA samples. Up to 45 μg RNA can be purified in a volume as low as 10 μl. Purification can be fully automated on the QIAcube Connect.

Performance

The RNeasy MinElute Cleanup Kit provides high-quality total RNA, free from impurities or enzymatic inhibitors, with A260/A280 ratios of 1.9–2.1 (see figure " High-quality RNA"). RNA amounts corresponding to less than one cell (as little as 1 pg) can be concentrated (see figure " Concentration of RNA"). A large amount of RNA (up to 45 µg) can be purified and is suitable for use in sensitive assays (see figure " Reliable cleanup of RNA").  Reaction volumes can be kept small in downstream applications, giving increased reaction efficiency. The high purity RNA allows more of the sample to be used in reactions without inhibition (see figure " Efficient removal of real-time RT-PCR inhibitors").
See figures

Principle

The RNeasy MinElute Cleanup Kit is designed to purify and concentrate RNA from enzymatic reactions (e.g., labeling, in vitro transcription), RNA isolated by alcohol-precipitation and organic-extraction methods, as well as to desalt RNA samples, and concentrate RNA prepared by silica-membrane procedures (e.g., PAXgene Blood RNA preps). RNeasy technology simplifies total RNA isolation by combining guanidine-isothiocyanate lysis with silica-membrane purification.

Procedure

Guanidine-isothiocyanate–containing lysis buffer and ethanol are added to the sample to create conditions that promote selective binding of RNA to the RNeasy MinElute membrane. The sample is then applied to the RNeasy MinElute spin column. RNA binds to the silica-membrane, contaminants are efficiently washed away, and high-quality RNA is eluted in water.

Enzymatic reactions or crude RNA preps are simultaneously cleaned up and concentrated in less than 15 minutes. In comparison, time-consuming concentration and cleanup by alcohol precipitation can result in loss of RNA, especially from small samples. The RNeasy MinElute procedure is faster than vacuum centrifugation, which only concentrates the sample without removing salts and other impurities. The unique design of RNeasy MinElute spin columns enables concentration of purified RNA to as little as 10 µl for downstream applications such as microarray analysis and real-time RT-PCR. Purification can be fully automated on the QIAcube.

Applications

RNA purified with RNeasy MinElute technology is high-quality and ideal for use in all applications including:

  • Northern, dot, and slot blotting
  • End-point RT-PCR
  • Quantitative, real-time RT-PCR
  • Array analysis
  • Poly A+ RNA selection

Supporting data and figures

Specifications

FeaturesSpecifications
ApplicationsPCR, qPCR, real-time PCR, microarray
FormatMinElute Spin column
Sample amount200 µl
Elution volume10–14 µl
ProcessingManual
Main sample type(Crude) RNA preps
Purification of total RNA, miRNA, poly A+ mRNA, DNA or proteinRNA
Time per run or per prep<15 minutes
TechnologySilica technology
Yield45 µg

Resources

Kit Handbooks (1)
Safety Data Sheets (1)
Download Safety Data Sheets for QIAGEN product components.
Supplementary Protocols (2)
There are two protocols: follow Protocol 1 if you want to purify total RNA containing miRNA, or follow Protocol 2 if you want to purify small RNA (includes miRNA, 5S rRNA, and tRNA) and larger RNA (>200 nt) separately.
Quick-Start Protocols (1)

Publications

Silencing of stathmin induces tumor-suppressor function in breast cancer cell lines harboring mutant p53.
Alli E; Yang JM; Hait WN;
Oncogene; 2006; 26 (7):1003-12 2006 Aug 14 PMID:16909102
The extracellular nucleotide UTP is a potent inducer of hematopoietic stem cell migration.
Rossi L; Manfredini R; Bertolini F; Ferrari D; Fogli M; Zini R; Salati S; Salvestrini V; Gulinelli S; Adinolfi E; Ferrari S; Di Virgilio F; Baccarani M; Lemoli RM;
Blood; 2006; 109 (2):533-42 2006 Sep 28 PMID:17008551
The lspA gene, encoding the type II signal peptidase of Rickettsia typhi: transcriptional and functional analysis.
Rahman MS; Ceraul SM; Dreher-Lesnick SM; Beier MS; Azad AF;
J Bacteriol; 2006; 189 (2):336-41 2006 Nov 10 PMID:17098907
Selection and cloning of poly(rC)-binding protein 2 and Raf kinase inhibitor protein RNA activators of 2',5'-oligoadenylate synthetase from prostate cancer cells.
Molinaro RJ; Jha BK; Malathi K; Varambally S; Chinnaiyan AM; Silverman RH;
Nucleic Acids Res; 2006; 34 (22):6684-95 2006 Dec 1 PMID:17145707
Additional freeze hardiness in wheat acquired by exposure to -3 degreesC is associated with extensive physiological, morphological, and molecular changes.
Herman EM; Rotter K; Premakumar R; Elwinger G; Bae H; Ehler-King L; Chen S; Livingston DP 3rd;
J Exp Bot; 2006; 57 (14):3601-18 2006 Sep 12 PMID:16968883

FAQ

Which kit should I use for RNA isolation from Cartilage?

Due to the complex nature of cartilage we would recommend to use the RNeasy Lipid Tissue Kit. Follow the standard tissue protocol in the RNeasy Lipid Tissue Kit Handbook.

To help you choose the correct RNeasy kit for the isolation of total RNA from different types of tissue, please refer to our Kit Selection Guide.

FAQ ID -1026
Do you have a protocol for purification of miRNA from animal cells using the RNeasy Plus Mini Kit and RNeasy MinElute Cleanup Kit?
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
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
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
What is the maximum binding capacity of RNeasy spin columns?
The maximum binding capacity of the RNeasy Mini spin columns is 100 ug RNA. It is 1 mg for RNeasy Midi columns and 6 mg for RNeasy Maxi columns. The maximum RNA binding capacity of the RNeasy MinElute spin columns is 45 µg.
FAQ ID -290
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
Can QIAquick Kits be used to clean up RNA samples?
Although it is possible to use the QIAquick Nucleotide Removal Kit and QIAquick PCR Purification Kit for RNA purification, the conditions are not optimized for RNA, nor are RNase-free conditions guaranteed. The RNeasy MinElute Cleanup Kit is recommended for clean-up, concentration and desalting of RNAs above 200 bases in length.
FAQ ID -490
Are RNeasy spin columns sold separately?
At this time, RNeasy spin columns are not sold separately.
FAQ ID -159
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
Can I use the RNeasy MinElute Cleanup Kit to clean up my in vitro transcription reaction?
Yes. RNeasy MinElute Cleanup Kit can also be used to clean up RNA following DNase digestion, or from crude RNA preparations following organic extraction or alcohol-precipitation.
FAQ ID -429
What is the composition of Buffer RDD?
The exact composition of Buffer RDD is proprietary. Buffer RDD is an important component of the RNase-Free DNase Set, which is used in combination with most RNeasy Kits. The composition and salt concentration of Buffer RDD provides efficient on-column digestion of DNA and also ensures that the RNA remains bound to the column.
FAQ ID -2800
What is the maximum volume of RNA in solution that can be used with the QuantiTect Whole Transcriptome Kit?

A maximum of 5 µl RNA eluate from RNeasy extraction procedures can be added to the reverse-transcription reaction with the QuantiTect Whole Transcriptome Kit.

 

 

FAQ ID -1616
Can I clean up my DNase treated RNA samples using RNeasy columns?
Yes. The RNeasy MinElute Cleanup Kit has been developed specifically for cleaning up and concentrating RNA samples. You can also follow the protocols for RNA cleanup in the RNeasy Mini and RNeasy Midi/Maxi Handbook.
FAQ ID -286
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
What is the minimum elution volume when using the RNeasy MinElute Cleanup Kit?
The minimum elution volume for the RNeasy MinElute Spin columns used in the RNeasy MinElute Cleanup Kit is 10 ul.
FAQ ID -432
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
What is the difference between Buffers RLT and RLT Plus?

In comparison to Buffer RLT of, e.g., the RNeasy Mini Kit, Buffer RLT Plus of the RNeasy Plus Mini Kit and RNeasy Plus 96 Kit also contains a proprietary blend of detergents that aid in the binding of genomic DNA to the gDNA Eliminator Mini Spin Columns, or to the gDNA Eliminator 96 plate respectively.

FAQ ID -1043
How do I clean up RNA preparations containing miRNA?

RNA preparations containing miRNA can be cleaned up by modifying* the cleanup protocols listed in the handbooks of the RNeasy Mini Kit or the RNeasy MinElute Cleanup Kit .

 

* Modify the cleanup protocol at step 2, by increasing the volume of ethanol (96-100%) from 250 µl to 950 µl.

FAQ ID -3002
What is the binding capacity of the RNeasy MinElute Cleanup Kit column?
The maximum binding capacity of the RNeasy MinElute Spin Column supplied in the RNeasy MinElute Cleanup Kit is 45 ug of RNA.
FAQ ID -430
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
Can I buy the RNeasy Mini columns, RNeasy MinElute columns, RNeasy Midi columns or the RNeasy Maxi columns separately?

We do not sell the RNeasy MinElute columns, RNeasy Mini columns, RNeasy Midi columns or the RNeasy Maxi columns separately.

In general, we always provide extra volume of buffers in our kits to account for pipetting errors and such. If you are left with extra buffers after using up all the columns in a kit, please refer to the Material Safety Data Sheet for respective kit to dispose off any unused buffers.

FAQ ID - 3388
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
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
Do I need to use RNase inhibitors with the RNeasy Kits?

No. The addition of beta-mercaptoethanol to lysis buffer RLT used in the RNeasy Kits is sufficient to inactivate any RNases in your sample. 

FAQ ID -813
Have you observed co-amplification of genomic DNA from RNA templates used in the QuantiTect Whole Transcriptome Procedure?

No, we have never observed coamplification of genomic DNA from RNA templates used in the QuantiTect Whole Transcriptome protocol when using RNA purified with RNeasy Kits without on-column DNase digestion.

 

 

FAQ ID -1619
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
How can I ensure complete genomic DNA removal when using the RNase-Free DNase Set?

To ensure efficient gDNA removal when doing an on-column digest using the RNase-Free DNase Set in combination with RNeasy Mini the following factors are crucial:

  • prevent overloading by adjusting the amount of starting material to no more than the maximum amounts recommended in the RNeasy Mini Handbook
  • ensure complete disruption and homogenization of the starting material as instructed in the section 'Disruption and homogenization of starting materials' of the handbook
  • strictly follow the protocol for on-column DNase Digestion in Appendix D of the RNeasy Mini Handbook (you can let wash buffer RW1 incubate on the column for 3-5 minutes before centrifuging to enhance removal of excess gDNA prior to applying the enzyme)

In the rare case that trace amounts of genomic DNA are still detectable in sensitive downstream applications such as e.g., realtime RT-PCR, an in-solution digest using the RNase-Free DNAase set can be performed. Instructions are presented in Appendix C of the RNeasy MinElute Cleanup Handbook.

Alternatively, a second on-column digest can be carried out in future preparations, immediately following the RW1 wash after the first incubation with DNase.

FAQ ID -1087
What happens if I spin my lysate on the RNeasy Spin Columns at maximum speed?
Spinning at maximum speed is fine, since binding of RNA to the columns will also be efficient. Instead, the critical issue is not to spin the columns below the minimum speeds recommended in the RNeasy Handbooks.
FAQ ID -514
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 do you ensure that concentrated RNA is purified from saliva using the RNeasy Protect Saliva Mini Kit?

The RNeasy Protect Saliva Mini Kit is based on RNeasy MinElute technology, which allows elution volumes as low as 10-14 µl, thereby concentrating saliva RNA.

 

FAQ ID -1212
Why do I have to add beta-mercaptoethanol (beta-ME) to lysis Buffer RLT of the RNeasy Kits?

When working with RNA, care must be taken to avoid degradation by RNases, which are extremely stable and active. Intracellular RNases are released during the lysis step of the RNA isolation procedure and must be rapidly and thoroughly inactivated to obtain high-quality RNA.

Beta-mercaptoethanol (ß-ME) is a reducing agent that will irreversibly denature RNases by reducing disulfide bonds and destroying the native conformation required for enzyme functionality. In combination with the strong, but temporary denaturing effects of guanidinium isothiocyanate (GITC) contained in buffer RLT of the RNeasy Kits, any RNases present in the material to be extracted from will be completely inactivated.

FAQ ID -101
What should I do if I suspect that my RNA preparation contains RNase contamination?

If you suspect that your RNA preparation contains RNase contamination, repurify the preparation using a RNeasy Mini Kit or RNeasy MinElute Cleanup Kit.

.

FAQ ID -2661
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