RNeasy Lipid Tissue Mini Kit

For purification of up to 100 µg total RNA from fatty tissues and other types of tissue

S_1270_GEF_RNALT0191

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RNeasy Lipid Tissue Mini Kit (50)

Cat. No. / ID:   74804

50 RNeasy Mini Spin Columns, Collection Tubes (1.5 ml and 2 ml), QIAzol Lysis Reagent, RNase-free Reagents and Buffers
The RNeasy Lipid Tissue Mini 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

Features

  • Optimized lysis conditions for fatty tissues and other tissues
  • High yields of total RNA without phenol contamination
  • High-quality RNA for all downstream applications

Product Details

The RNeasy Lipid Tissue Mini Kit includes QIAzol Lysis Reagent for lysing fatty tissues and other types of tissue, and RNeasy spin columns for purifying up to 100 µg of high-quality RNA. The kit can be automated using the QIAcube Connect. Tissue samples can be conveniently stabilized using RNAprotect Tissue Reagent (nonfatty tissues only) or Allprotect Tissue Reagent, and efficiently disrupted using a TissueRuptor or TissueLyser system. For larger samples, the RNeasy Lipid Tissue Midi Kit (spin-column binding capacity of 1 mg RNA) is also available.

Performance

The RNeasy Lipid Tissue protocol integrates QIAzol lysis with RNeasy RNA isolation for high yields of total RNA from fatty tissues with an average yield of RNA from 10 mg of brain of 10 µg, and 2.4 µg of RNA from a 10 mg sample of adipose tissue. RNeasy Lipid Tissue kits provide efficient isolation of high-quality total RNA without phenol carryover (see figure " High yields of RNA without phenol carryover"). The RNA from fatty tissues is suitable for downstream applications including real-time RT-PCR (see figure " Real-time analysis of high-quality RNA").
See figures

Principle

RNeasy Lipid Tissue Kits are optimized for use with fatty tissues, such as brain and adipose tissue. The convenient RNeasy Lipid Tissue protocol integrates optimized phenol/guanidine-based lysis with proven RNeasy purification for isolation of high yields of high-quality total RNA. The combination of organic extraction and chaotropic disruption contributes to the high lysis efficiency of QIAzol Lysis Reagent. Since the RNeasy procedures enrich for mRNA and other RNA species >200 nucleotides, the total RNA yield does not include 5S rRNA, tRNA, and other low-molecular-weight RNAs, which make up 15-20% of total cellular RNA.

Procedure

Tissue samples 10–100 mg are homogenized in QIAzol Lysis Reagent. After addition of chloroform, the homogenate is separated into aqueous and organic phases by centrifugation. The upper, aqueous phase is extracted, and ethanol is added to provide appropriate binding conditions. The sample is then applied to the RNeasy spin column, where the total RNA (up to 100 µg) binds to the membrane and phenol and other contaminants are efficiently washed away. High-quality RNA is then eluted in 30–100 µl of RNase-free water water (see figure " RNeasy Lipid Tissue Mini procedure").
See figures

Applications

RNeasy Lipid Tissue Kits provide easy and efficient isolation of high-quality RNA for all downstream applications, including array analysis and real-time RT-PCR.

Supporting data and figures

Specifications

FeaturesSpecifications
ApplicationsNGS, PCR, real-time PCR, microarray
Sample amount10–100 mg
Yield2.4–10 mg
TechnologySilica technology
ProcessingManual
Purification of total RNA, miRNA, poly A+ mRNA, DNA or proteinRNA
Elution volume30–100 µl
Main sample typeFatty tissue samples
Time per run or per prep45 minutes
FormatSpin column

Publications

Lipopolysaccharide activates an innate immune system response in human adipose tissue in obesity and type 2 diabetes.
Creely SJ; McTernan PG; Kusminski CM; Fisher fM; Da Silva NF; Khanolkar M; Evans M; Harte AL; Kumar S;
Am J Physiol Endocrinol Metab; 2006; 292 (3):E740-7 2006 Nov 7 PMID:17090751
Chronic ethanol feeding to rats decreases adiponectin secretion by subcutaneous adipocytes.
Chen X; Sebastian BM; Nagy LE;
Am J Physiol Endocrinol Metab; 2006; 292 (2):E621-8 2006 Oct 17 PMID:17047161
Targeting an E2F site in the mouse genome prevents promoter silencing in quiescent and post-mitotic cells.
Tavner F; Frampton J; Watson RJ;
Oncogene; 2006; 26 (19):2727-35 2006 Oct 30 PMID:17072340
Paternally biased X inactivation in mouse neonatal brain.
Wang X; Soloway PD; Clark AG;
Genome Biol; 2010; 11 (7):R79 2010 Jul 27 PMID:20663224
A study of alternative splicing in the pig.
Nygard AB; Cirera S; Gilchrist MJ; Gorodkin J; Jørgensen CB; Fredholm M;
BMC Res Notes; 2010; 3 :123 2010 May 5 PMID:20444244

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
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 smallest sample size that can be used with RNeasy Mini Kits?
We have purified RNA from as little as 0.5 mg tissue or 100 cells using the RNeasy Mini Kit and verified the quality by northern blot analysis and RT-PCR, respectively. In principle, there is no minimum sample amount for RNeasy technology as all RNA will bind to the spin column. However, due to a very small amount of residual RNA irreversibly bound to the silica membrane, not all RNA may elute at the final step of the isolation. The RNeasy Micro Kit can purify RNA from as little as one cell.
FAQ ID -485
Is it possible to isolate both RNA and recombinant 6xHis-tagged protein from the same sample?
We have no experimental data for this application. However, buffer RLT of the RNeasy Kits for RNA isolation does not contain substances incompatible with Ni-NTA purification of His-tagged proteins. It should be possible to first extract RNA from a sample by following the RNeasy procedure, save the flow-through from the binding step as well as from the RW1 wash, and apply the combined fractions onto a Ni-NTA column for binding of His-tagged proteins. Follow our recommendations for purification of 6xHis-tagged proteins using Ni-NTA resins outlined in the QIAexpressionist handbook.
FAQ ID -532
Can the AllPrep DNA/RNA/Protein Mini Kit be used with fibrous or lipid tissues?

The AllPrep DNA/RNA/Protein Mini Kit is optimized for use with easy-to-lyse tissues. For fibrous (e.g., heart) and lipid tissues (e.g., brain), we recommend using a portion of the tissue sample for RNA purification with the RNeasy Fibrous Tissue Mini Kit and RNeasy Lipid Tissue Mini Kit, respectively.

 

 

 

FAQ ID -1579
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
When using QIAzol Lysis Reagent for RNA extraction, I see a pinkish colored aqueous phase! Is it OK?
Yes. Depending on the starting material the aqueous phase might be colored. It will not harm the RNA extraction procedure. It may be a hint at overloading.
FAQ ID -534
Do you have a protocol for the isolation of RNA from bacterial cultures using RNAprotect Bacteria Reagent and QIAzol Lysis Reagent?
Yes, please follow the protocol in the RNAprotect Bacteria Reagent Handbook in Appendix D:  Stabilization and Purification of Bacterial RNA Using RNAprotect Bacteria Reagent, the RNeasy Lipid Tissue Mini Kit, and the TissueLyser.
FAQ ID -1020
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
Do you have a protocol for purification of total RNA from plant latex?

Yes, please follow the User-Developed Protocol 'Purification of total RNA from plant latex using the RNeasy Lipid Tissue Mini Kit' (RY33).

 

 

 

FAQ ID -1694
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
Do you have a protocol for the isolation of genomic DNA and/or proteins from fatty tissue treated with QIAzol?
FAQ ID -955
Do you have a protocol for purification of total RNA from fatty tissues using QIAzol Lysis Reagent and MaXtract High Density?

Yes, we have the following protocols:

  • Purification of total RNA from fatty tissues using QIAzol Lysis Reagent, MaXtract High Density, and the TissueRuptor (RY29).
  • Purification of total RNA from fatty tissues using QIAzol Lysis Reagent, MaXtract High Density, and the TissueLyser (RY30).
  • Purification of total RNA from fatty tissues using the RNeasy Lipid Tissue Mini Kit and MaXtract High Density (RY31).
FAQ ID -1550
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
Which chloroform should I use for the RNeasy Lipid Tissue Kit?
In general we recommend to use Molecular Biology or higher grade chloroform.
FAQ ID -516
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
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
How is the RNeasy Lipid Tissue Mini Kit different from the RNeasy Mini Kit?
The RNeasy Lipid Tissue Kits have been designed for the optimal lysis of tissues rich in fat, such as brain and adipose tissues. Lysis and homogenization is performed using QIAzol, a phenol/guanidine-based lysis reagent. The RNA is then purified from the aqueous fraction using a RNeasy spin column. The RNeasy Lipid Tissue Kit combines optimal lysis of fatty tissues with silica membrane technology, resulting in high-quality total RNA.
FAQ ID -468
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
Do you have a protocol for purification of total RNA from plant tissue with the RNeasy Lipid Tissue Mini Kit?

Yes, please follow the User-Developed Protocol 'Purification of total RNA from plant tissue using the RNeasy Lipid Tissue Mini Kit ' (RY32).

 

 

FAQ ID -1693
Can the MaXtract High Density Tube be used with QIAzol to isolate RNA?
FAQ ID -1304
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
Which kit should be used to extract RNA from adipose tissue, brain, and other fatty animal tissues?
The RNeasy Lipid Tissue Mini and Midi Kits are designed to extract RNA from up to 100mg and 500mg of fatty tissue, respectively.
FAQ ID -467
Why are samples centrifuged at 4°C after the addition of chloroform when using RNeasy Lipid Tissue Kits?

Phase separation by centrifugation at 4°C after adding chloroform to the samples when using RNeasy Lipid Tissue Kits ensures minimizing genomic DNA contamination. Subsequent centrifugation steps with the RNeasy Mini Spin Columns have to be carried out at room temperature to prevent buffer salt precipitation, guarantee optimum binding of RNA to the column and obtain highest RNA yields.

FAQ ID -533
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
What are the 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
Can I homogenize samples in QIAzol using the QIAshredder?
Yes
FAQ ID -501
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
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
Can I use the RNeasy Mini Kit or RNeasy 96 Kit with fewer than 100 cells?

Yes. The RNeasy Mini Kit and RNeasy 96 Kit have been used successfully to isolate RNA from fewer than 100 cells. We recommend adding 20 ng of carrier RNA to the cell lysate before loading it onto the RNeasy membrane. Please note that the carrier RNA will co-purify with cellular RNA. However, the small amounts of poly-A RNA used as carrier RNA do not interfere with subsequent RT-PCR, even when oligo-dT is used for reverse transcription. Reverse-transcription reactions typically contain a large excess of oligo-dT, and the small amounts of poly-A used as carrier RNA are insignificant in comparison.

Alternatively, the RNeasy Micro Kit can be used for isolating RNA from up to 5x 105 cells. The RNeasy Micro procedure uses a novel technology to purify RNA from small amounts of tissues or cells (as little as 1 cell).

FAQ ID -372
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