QIAamp DNA Stool Mini Kit
For isolation of DNA from stool
- Rapid isolation of high-quality, ready-to-use DNA
- No organic extraction or alcohol precipitation
- Consistent, high yields
- Complete removal of contaminants and inhibitors
The QIAamp DNA Stool Mini Kit provides silica membrane-based purification of up to 30 μg genomic, bacterial, viral, and parasite DNA from fresh or frozen human stool or other sample types with high concentrations of PCR inhibitors. The combined action of InhibitEX, a unique adsorption resin, and an optimized buffer leads to removal of PCR inhibitors. The convenient QIAamp spin-column procedure provides purification in only 50 minutes. Purification of DNA using the QIAamp DNA Stool Mini Kit can be automated on the QIAcube.
The QIAamp® DNA Stool Mini Kit (50) (cat. no. 51504) and the InhibitEX Tablets (100) (cat. no. 19590) are no longer manufactured. Instead, we offer you the QIAamp Fast DNA Stool Mini Kit (50) (cat. no. 51604) as an alternative product.
The QIAamp DNA Stool Mini Kit allows rapid purification of DNA from fresh or frozen human stool or other sample types with high concentrations of PCR inhibitors. Up to 220 mg stool can be processed routinely, and larger amounts can be processed with additional Buffer ASL. Typical yields of 10–30 µg are obtained in 50 minutes, and DNA is eluted in 200 µl. The purified DNA is sized up to 50 kb. DNA of this length denatures completely and has the highest amplification efficiency. Highly pure DNA is ready for direct use in downstream amplification reactions (see figure " Removal of PCR inhibitors").
DNA that has been purified using the QIAamp DNA Stool Mini Kit can be used in a wide range of downstream applications, including PCR and quantitative real-time PCR, infectious disease research, and screening.
DNA binds specifically to the QIAamp silica-gel membrane while contaminants pass through. No phenol–chloroform extraction is required. PCR inhibitors are removed by the combined action of InhibitEX, a unique adsorption resin, and an optimized buffer. Rigorous lysis using proteinase K ensures high yields of all types of DNA common in stool, including colorectal epithelial cells, bacteria, viruses and other gastrointestinal pathogens.
Highly pure DNA ready for direct use in downstream amplification reactions is purified in about 50 minutes. QIAamp sample preparation technology is fully licensed.
The QIAamp DNA Stool Mini Kit is for isolation of genomic, bacterial, viral, and parasite DNA from the following sample types:
|Main sample type||Stool samples|
|Purification of total RNA, miRNA, poly A+ mRNA, DNA or protein||Genomic DNA, bacterial DNA, parasite DNA, viral DNA|
|Elution volume||200 µl|
|Sample amount||220 mg|
|Time per run or per prep||50 minutes|
|Processing||Manual (centrifugation or vacuum)|
It is strongly advised to follow the recommendations for preparing sample material provided in the corresponding Protocol Sheet to ensure reliable results.
Plasma: It is recommended to perform plasma separation immediately after blood collection when using EDTA or citrate as anticoagulant to prevent the release of genomic DNA into the plasma fraction.
Urine: Because circulating cell-free DNA in non-stabilized urine samples is rapidly degraded after sample collection due to high nuclease activity, eluates may contain no DNA or exhibit low DNA concentration. Therefore, it is recommended to stabilize urine samples. Even when using stabilized urine, it is recommended to perform a centrifugation step immediately after stabilization to prevent the release of genomic DNA from cells. Alternatively, non-stabilized urine samples can be processed immediately after collection and centrifugation using ATL-pretreatment and automated DNA extraction as described in the corresponding Protocol Sheet.
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.
The isolation of DNA from soil, food and sewage for use in PCR can be challenging due to a high levels of inhibitors in these samples (e.g. humic acids, tannic acids, lignins, and anthocyanins) which are often co-isolated with the DNA.
The QIAamp DNA Stool Mini Kit allows isolation of genomic DNA from fecal and soil samples with the efficient removal of PCR inhibitors.
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.).
The composition of Buffer AE is:
EDTA chelates divalent cations which are required for nuclease activity. While the genomic DNA (gDNA) extracted using QIAGEN products, should not have any nuclease activity, it is possible to introduce nucleases during repeated long-term access of the DNA. EDTA helps to prevent any nuclease activity introduced after the genomic DNA extraction procedures.
However, if the gDNA is stored frozen at -20oC or -80oC, nuclease activity is much reduced. It may be possible to leave EDTA out of the storage buffer without negative consequences when samples are kept under these conditions, and when repeated freeze-thaw cycles are avoided.
We do recommend however that gDNA be stored in a neutral to a slightly basic buffered solution (e.g. 10 mM Tris-Cl pH 8.5 to 9.0) to prevent DNA degradation by acid hydrolysis. Note that deionized water mostly has an acidic pH.
QIAGEN Proteinase K is a subtilisin-type protease, which cleaves at the carboxyl side of hydrophobic, aliphatic and aromatic amino acids. It is particularly suitable for short digestion times. It possesses a high specific activity over a wide range of temperatures and pH values with substantially increased activity at higher temperature. Soluble calcium is not essential for enzymatic activity. This means that EDTA, which is used to inhibit Mg2+-dependent enzymes such as nucleases, will not inhibit Proteinase K activity.
QIAGEN Protease is a broad-specificity Serine protease with high activity, cleaving preferentially at neutral and acidic residues. It is an economical alternative to Proteinase K for isolation of native DNA and RNA from a variety of samples.
For more information on activity of QIAGEN Protease and Proteinase K in various buffers please click here.
Yes, please follow either of the User-Developed Protocols:
Yes, please follow the User-Developed Protocol 'Isolation of DNA from formalin-preserved stool samples using the QIAamp DNA Stool Mini Kit' (QA27). Please contact Technical Service for this protocol.
Yes, please follow the User-Developed Protocol 'Isolation of bacterial DNA from soil using the QIAamp DNA Stool Mini Kit and QIAamp DNA Blood Midi Kit' (QA28).