QIAquick Gel Extraction Kit

For gel extraction/cleanup of up to 10 µg DNA (70 bp to 10 kb) from gels or enzymatic reactions

S_1341_DNA_QQ0799

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QIAquick Gel Extraction Kit (50)

Cat. No. / ID:  28704

For gel extraction or cleanup of 50 reactions: 50 QIAquick Spin Columns, Buffers, Collection Tubes (2 ml)
KitColumn
QIAquick Gel Extraction Kit
QIAquick PCR & Gel Cleanup Kit
QIAquick Spin Columns
Reactions
50
250
1000
The QIAquick Gel Extraction 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

  • Up to 95% recovery of ready-to-use DNA
  • Fast and convenient procedure
  • Cleanup of DNA up to 10 kb in three easy steps
  • Gel loading dye for convenient sample analysis
  • Combined kit for gel extraction and PCR cleanup

Product Details

The QIAquick Gel Extraction Kit provides spin columns, buffers, and collection tubes for silica-membrane-based purification of DNA fragments from gels (up to 400 mg slices) or enzymatic reactions. DNA ranging from 70 bp to 10 kb is purified using a simple and fast bind-wash-elute procedure and an elution volume of 30–50 µl. An integrated pH indicator allows easy determination of the optimal pH for DNA binding to the spin column. The QIAquick PCR & Gel Cleanup Kit also provides buffers for purification of PCR products >100 bp and DNA of up to 10 kb. The procedure can be fully automated on the QIAcube Connect.

For optimal results it is recommended to use this product together with QIAvac 24 Plus.

Performance

The QIAquick Gel Extraction Kit enables removal of nucleotides, enzymes, salts, agarose, ethidium bromide, and other impurities from samples, ensuring up to 80% recovery of DNA (see figure " High recoveries from gels"). Using a microcentrifuge or vacuum manifold, DNA ranging from 70 bp to 10 kb is purified from 1–24 samples. Purified DNA can be used, for example, in sequencing (see figure " Reliable sequencing after gel extraction"). DNA fragments smaller than 70 bp or larger than 10 kb should be extracted with the QIAEX II Gel Extraction System.

The QIAquick PCR Purification procedure removes primers, nucleotides, enzymes, mineral oil, salts, and other impurities from DNA samples (see figure " Complete primer removal after PCR"). Using a microcentrifuge or vacuum manifold, DNA ranging from 100 bp to 10 kb is purified.

See figures

Principle

QIAquick Kits contain a silica membrane assembly for binding of DNA in high-salt buffer and elution with low-salt buffer or water. The purification procedure removes primers, nucleotides, enzymes, mineral oil, salts, agarose, ethidium bromide, and other impurities from DNA samples (see figure " High recoveries from gels"). Silica-membrane technology eliminates the problems and inconvenience associated with loose resins and slurries. Specialized binding buffers are optimized for specific applications and promote selective adsorption of DNA molecules within particular size ranges.

Gel loading dye

To enable faster and more convenient sample processing and analysis, gel loading dye is provided. GelPilot Loading Dye contains three tracking dyes (xylene cyanol, bromophenol blue, and orange G) to facilitate the optimization of agarose gel run time and prevent smaller DNA fragments migrating too far (see figure  "GelPilot Loading Dye").

See figures

Procedure

The QIAquick system uses a simple bind-wash-elute procedure (see flowchart " QIAquick and MinElute procedure"). Gel slices are dissolved in a buffer containing a pH indicator, allowing easy determination of the optimal pH for DNA binding, and the mixture is applied to the QIAquick spin column (see figure " pH Indicator Dye"). Nucleic acids adsorb to the silica membrane in the high-salt conditions provided by the buffer. Impurities are washed away and pure DNA is eluted with a small volume of low-salt buffer provided or water, ready to use in all subsequent applications.

Handling

QIAquick spin columns are designed to provide two convenient handling options. The spin columns fit into a conventional table-top microcentrifuge or onto any vacuum manifold with luer connectors, such as the QIAvac 24 Plus with QIAvac Luer Adapters. The QIAquick Gel Extraction Kit, in addition to other QIAGEN spin-column-based kits, can be fully automated on the QIAcube Connect, enabling increased productivity and standardization of results (see figures "Spin column handling options  A,  B,  C, and  D" and " QIAcube Connect").

See figures

Applications

DNA fragments purified with the QIAquick system are ready for direct use in all applications, including sequencing, ligation and transformation, restriction digestion, labeling, microinjection, PCR, and in vitro transcription.

Supporting data and figures

Specifications

FeaturesSpecifications
Binding capacity10 µg
FormatTube
Fragment size70 bp – 10 kb
Recovery: oligonucleotides dsDNARecovery: dsDNA fragments
ProcessingManual
Removal <10mers 17–40mers dye terminator proteinsRemoval <10mers
Elution volume30–50 µl
TechnologySilica technology
Sample type: applicationsDNA: PCR reactions

Resources

Kit Handbooks (2)
Safety Data Sheets (1)
Scientific Posters (1)
Certificates of Analysis (1)

Publications

STAT5 represses BCL6 expression by binding to a regulatory region frequently mutated in lymphomas.
Walker SR; Nelson EA; Frank DA;
Oncogene; 2006; 26 (2):224-33 2006 Jul 3 PMID:16819511

FAQ

I bound an 11 kb DNA fragment to a QIAquick column; is it completely lost?

Larger DNA fragments bind more tightly to the QIAquick columns. It is difficult to predict whether a DNA fragment larger than 10 kb can be efficiently recovered, because this depends on base composition as well as fragment size. If the fragment is only a few kb larger than the 10 kb limit, it can be helpful to heat the elution buffer EB to 60°C and let it incubate on the column for a few minutes before centrifuging. However, please note that it will become less likely to recover your sample the larger the fragment size is. As we cannot guarantee recovery of fragments larger than the maximum cutoff size, we do not recommend to purify such fragments using QIAquick Kits.

The QIAEX II Kit can be used to extract DNA fragments up to 50 kb from agarose or polyacrylamide gels.

 

FAQ ID -756
Are Buffer PB of the QIAquick PCR Purification Kit and Buffer QG of the QIAquick Gel Extraction Kit interchangeable?

Buffer PB of the QIAquick PCR Purification Kit cannot be used to extract DNA from agarose gels. However, Buffer QG of the QIAquick Gel Extraction Kit can be used to remove salt and proteins from enzymatic reactions by adding 3 volumes of Buffer QG and 1 volume of isopropanol to the reaction and proceeding with step 6 of the Gel Extraction Spin Protocol in the QIAquick Spin Handbook. See the QIAquick Spin Handbook for a list of reactions which can be cleaned up with the various QIAquick kits.

FAQ ID -786
Are QIAprep and QIAquick Spin columns interchangeable?
No. While columns from the QIAprep Spin Miniprep Kit and the QIAquick PCR Purification- and Gel Extraction Kits are based on silica-gel-membrane technology, each is designed to work optimally within its own kit format. In addition, the binding capacity and DNA recovery size cut-offs of the QIAprep and QIAquick Spin columns are different. QIAprep Spin columns bind up to 20 ug of plasmid DNA up to 50 kb in length, while the QIAquick Spin columns bind up to 10 ug of DNA with a maximum fragment size of 10 kb.
FAQ ID -311
Are the columns of the QIAquick PCR Purification-, Gel Extraction-, and Nucleotide Removal Kit interchangeable?
Yes - all QIAquick Spin Kits contain identical columns, but different binding buffers optimized for each specific application.
FAQ ID -577
Can I store agarose gel slices containing DNA for gel extraction at a later point?
Cut out the slice of agarose containing the DNA fragment of interest, and store it at 4oC in an Eppendorf tube sealed with Parafilm.
FAQ ID -313
How can I improve recoveries when using the QIAquick Kits?

Buffer PE did not contain ethanol

Ethanol must be added to Buffer PE (concentrate) before use. Repeat procedure with correctly prepared Buffer PE.

Inappropriate elution buffer

DNA will only be eluted efficiently in the presence of low-salt buffer (e.g., Buffer EB: 10 mM Tris·Cl, pH 8.5) or water. Elution efficiency is strongly dependent on the salt concentration and pH of the elution buffer. Contrary to adsorption, elution is most efficient under basic conditions and low salt concentrations. DNA is eluted with 50 or 30 µl of the provided Buffer EB (10 mM Tris·Cl, pH 8.5), or water. The maximum elution efficiency is achieved between pH 7.0 and 8.5. When using water to elute, make sure that the pH is within this range. In addition, DNA must be stored at –20°C when eluted with water since DNA may degrade in the absence of a buffering agent. Elution with TE (10 mM Tris·Cl, 1 mM EDTA, pH 8.0) is possible, but not recommended because EDTA may inhibit subsequent enzymatic reactions.

Elution buffer incorrectly dispensed

Add elution buffer to the center of the QIAquick membrane to ensure that the buffer completely covers the membrane. This is particularly important when using small elution volumes (30 µl).

FAQ ID -180
How do I perform a DNA precipitation to concentrate my sample?
  • Add 1/10 volume of 3 M Na-Acetate pH 5.2, and 2 to 2.5 volumes of ice-cold 100% ethanol to the DNA sample
  • Mix, and store at –20°C for at least 1 h to precipitate the DNA
  • Recover the precipitated DNA by centrifugation at full speed in a microcentrifuge for 15–20 min
  • Pour off the ethanol and wash the pellet twice with room-temperature 70% ethanol
  • Allow the DNA pellet to air-dry
  • resuspend the DNA in a suitable volume of sterile TE buffer or distilled water
FAQ ID -305
Will the QIAquick PCR Purification Kit remove sufficient SYBR Green from real-time PCR reactions to allow sequencing?

Based on our experience, the QIAquick PCR Purification Kit removes SYBR Green dye efficiently from PCR reactions.

We strongly assume that the QIAquick Gel Extraction Kit will be equally efficient in removing this dye, however, we recommend a 5 min incubation with wash Buffer PE on the QIAquick spin column at step 10 of the QIAquick Gel Extraction Kit Protocol. Efficiency of SYBR Green dye removal has to be validated by the enduser.

 

FAQ ID -637
Do you have protocols for multiple extractions of DNA fragments from agarose gels?

Yes, please follow the Supplementary Protocols 'High-throughput gel extractions using the QIAquick 96 PCR Purification Kit' (QQ03).  Please contact your local QIAGEN Technical Service for this protocol.

FAQ ID -944
Can a QIAquick Gel Extraction Kit be used to obtain RNA from a formaldehyde gel?

Yes. The QIAquick Gel Extraction Kit for extraction of DNA from gels can also be used for RNA gel extraction. Please see a user-developed procedure below, which was kindly provided by J. Knobloch, Heinrich Heine University, Düsseldorf, Germany. Note that this protocol has not been thoroughly tested and optimized by QIAGEN. QIAquick Gel Extraction Kits are not guaranteed to be RNase-free.

  1. Excise the RNA fragment from the formaldehyde agarose gel with a clean, sharp scalpel.
  2. Weigh the gel slice, and record the weight. Soak the gel slice in TE buffer for 25 min at room temperature with gentle shaking.
  3. Remove the gel slice from the TE buffer, and place it in a colorless tube. Add 6 volumes of Buffer QG to 1 volume of gel, based on the gel weight (100 mg ~ 100 µl).
  4. Incubate at 58°C for 25 min. To help dissolve the gel, mix by vortexing the tube every 2–3 min during the incubation.
  5. Continue the QIAquick Gel Extraction Kit Protocol (using a microcentrifuge) in the QIAquick Spin Handbook, beginning with step 4.
Please click here  for Figure 1. 

Figure 1:

A. Total RNA was isolated from the parasitic blood fluke Schistosoma mansoni using the RNeasy Mini Kit and run on a formaldehyde agarose (1.2%) gel. (Note: The 28S rRNA in S. mansoni contains a break site so that the rRNA splits into two parts, which run on a gel at the same size as the 18S rRNA.) The rRNA bands were excised and treated as described above (left lane) or using 10 volumes of Buffer QG in step 3 (right lane).

B. The extracted RNA was then analyzed on a new formaldehyde agarose gel. (Data kindly provided by J. Knobloch, Department of Genetic Parasitology, Heinrich Heine University, Düsseldorf, Germany).

FAQ ID -133
Why does my DNA sample float out of the slot when loading it onto an agarose gel?

DNA fragments purified with the QIAGEN DNA Cleanup Systems, i.e., the QIAquick PCR Purification Kit, the MinElute Reaction Cleanup Kit, the QIAEX II Gel Extraction Kit etc. may float out of the loading wells of agarose gels due to residual ethanol carried over from the wash step with Buffer PE (despite the addtition of glycerol-containing loading buffer).

Use either of the following options to remove residual ethanol from the eluate:

  • re-purify the sample using a QIAquick-, or MinElute column, or QIAEX II resin
  • incubate the eluate at 56°C for 10 min to evaporate the ethanol
  • dry down the sample in a vacuum centrifuge, and resuspend the pellet in a small volume of sterile water
FAQ ID -205
Is it possible to clean up a methylation reaction containing bisulfite with QIAquick Cleanup Kits?
Yes, bisulfite containing methylation reactions can be cleaned up with our silica-based cleanup products, such as QIAquick and QIAEX II. Please see Goyon et al. (1994),  'Perpetuation of cytosine methylation in Ascobolus immersus implies a novel type of maintenance methylase', published in J Mol Biol. 1994 Jul 1;240(1):42-51, for a reference.
FAQ ID -519
Do you have information about the cleanup of single-stranded DNA (ssDNA) with QIAquick columns?

As a rule of thumb, single-stranded DNA binds to silica with approximately half the affinity of a double-stranded DNA fragment of the same length under the buffer conditions used in the QIAquick and MinElute Kits. Even though no systematic experimental data exists, we expect that recovery of ssDNA fragments of approximately 200 nucleotides and below will not be very efficient after cleanup using the QIAquick PCR Purification Kit or MinElute PCR Purification Kit. By comparison, it should be possible to purify fragments longer than 140 nucleotides using the QIAquick Gel Extraction Kit.

Note that recovery of single strand DNA is influenced to some degree also by factors such as base composition and secondary structure. It has to be determined empirically by the researcher if cleanup of single-stranded DNA with QIAquick columns yields satisfactory results.

FAQ ID -759
What is the composition of Buffer EB?

The composition of Buffer EB is:

  • 10 mM Tris-Cl, pH 8.5

Buffer EB is the elution buffer used in the QIAquick PCR, Gel Extraction, Nucleotide Removal Kits, and MinElute Kits for DNA cleanup, and the QIAprep Miniprep Kits for small-scale plasmid purification. The purified DNA can also be eluted in TE (10 mM Tris-Cl, 1 mM EDTA, pH 8.0), but the EDTA may inhibit subsequent enzymatic reactions.

FAQ ID -199
What is the small band below my fragment of interest on an agarose gel after DNA cleanup using QIAquick?

Occasionally, DNA fragments eluted from the silica matrix of QIAquick, MinElute or QIAEX II Kits will contain denatured single-stranded DNA (ssDNA), appearing as a smaller band on an analytical gel. Under certain conditions, chaotropic agents (present in all silica-based DNA purification methods) can denature DNA fragments. This is a rare event that may be influenced by sequence characteristics such as the presence of inverted repeats or A–T-rich stretches.

Because salt and buffering agents promote renaturation of DNA strands, the following tips are recommended:

  • use the eluted DNA to prepare your downstream enzymatic reaction, but omit the enzyme. Incubate the reaction mix at 95°C for 2 minutes to reanneal the ssDNA, and allow the tube to cool slowly to room temperature before adding the enzyme and proceeding
  • alternatively, the DNA can be eluted from the silica-gel membrane or resin in 10 mM Tris buffer containing 10 mM NaCl. However, the salt concentration of the eluate must then be taken into consideration in downstream applications.
FAQ ID -148
Can I buy QIAquick and MinElute columns separately?

The QIAquick Spin Columns (100) (cat. no. 28115) in the QIAquick PCR Purification, Gel Extraction, Nucleotide Removal and PCR & Gel Cleanup kits are also sold separately from the kits.

The MinElute columns in the MinElute PCR Purification, Gel Extraction and Reaction Cleanup kits are not sold separately.

We always provide extra buffers in our kits so you can scale up reactions, add extra washes or allow for spillage.

FAQ ID -2460
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
How can I extract DNA from a polyacrylamide (PAGE) gel?

The QIAEX II and QIAquick Gel Extraction Kit can be used to extract DNA from polyacrylamide gels.

The QIAEX II Handbook contains a protocol for Polyacrylamide Gel Extraction. A specialized User-Developed Protocol (QQ05) is available when using the QIAquick Gel Extraction Kit for this purpose.

Both protocols require the preparation of a diffusion buffer and a disposable plastic column or syringe barrel containing a Whatman GF/C filter or siliconized glass wool. To ensure optimal diffusion, cut the gel slices as small as possible, and use 2 volumes of diffusion buffer per 1 volume of gel. Increasing incubation time (protocol step 3) may result in higher yields.

FAQ ID -120