CTAB Extraction Buffer is a widely-used reagent used to isolate DNA from plant tissues. Polysaccharides and polyphenols are problematic contaminants associated with DNA isolated from plants. CTAB Extraction Buffer effectively eliminates polysaccharides and polyphenols by employing the cationic detergent CTAB (hexadecyltrimethylammonium bromide or cetyltrimethylammounium bromide), and the polyphenol binding agent, Polyvinylpyrrolidone.
Traditional CTAB protocols typically require the homogenization of plant samples in CTAB Extraction Buffer prior to centrifugation to pellet debris and polysaccharides. The supernatant is then extracted using chloroform, and DNA is precipitated with alcohol. Isolated DNA is typically very clean.
CTAB Extraction Buffer is quality-control tested for sterility and consistency. It is a cost-effective and time-saving alternative to purchasing reagents and formulating homegrown buffers. This ready-to-use formula is available in 125 ml and 500 ml bottles.
NOTE: Traditional CTAB protocols require the use of chloroform, which is considered carcinogenic. For alternative methods that do not require chloroform, please see the Synergy™ 2.0 Plant DNA Extraction Kit.
CTAB Extraction Buffer Suggested Protocol
- Pulverize 100 mg of plant sample using a liquid nitrogen chilled mortar and pestle. Once processed, mix 100 mg of frozen powdered sample with 500 µl of CTAB Plant Extraction Buffer.
- Place the homogenate into a 60°C bath for 30 min.
- Centrifuge the homogenate for 10 minutes at 10,000 x g.
- Transfer the supernatant into a clean tube and add 5 µl of RNase (10 mg/ml in water) to the lysate. Incubate at room temperature for 15 minutes.
- Centrifuge for 5 minutes at 10,000 x g.
- Extract the lysate with equal volume of chloroform: isoamyl alcohol (24:1). Vortex for 5 seconds then centrifuge for a minute at 10,000 x g to separate the phases.
- Transfer the upper phase to a clean tube.
- Repeat step 7 until upper layer is clear. Transfer upper phase to a new tube.
- Add 0.7 volumes of isopropanol. Mix and incubate at -20°C for 15 minutes.
- Centrifuge for 10 minutes at 10,000 x g. Decant and wash the pellet with 70% ethanol.
- Decant without disturbing the pellet. Dry the pellet briefly in the SpeedVac (3 minutes at medium heat). Do not over-dry the DNA.
- Resuspend the DNA in 50 µl of TE buffer.
Isolation of Plant DNA using CTAB Protocol with a Spin Column
CTAB Buffer Comparison
Product Information Sheet
Stark, J. R.; Cardon, Z. G.; Peredo, E. L. Extraction of High-Quality, High-Molecular-Weight DNA Depends Heavily on Cell Homogenization Methods in Green Microalgae. Applications in Plant Sciences 2020, 8 (3), e11333. https://doi.org/10.1002/aps3.11333.