Cetyltrimethylammonium bromide, commonly known as CTAB buffer, is frequently used for DNA and RNA extraction. In this article, we provide a method for DNA or RNA extraction using the CTAB method.
CTAB is one of the cationic detergents that help to degrade or lysis the cell membrane and release other organelles including DNA and RNA.
CTAB, or cetyltrimethylammonium bromide, is indeed a cationic detergent. As a cationic detergent, CTAB has a positively charged hydrophilic (water-attracting) head and a hydrophobic (water-repelling) tail. This unique structure allows it to interact with cell membranes, disrupt their integrity, and facilitate the release of cellular components, including nucleic acids like DNA/RNA, during processes such as cell lysis in molecular biology experiments, particularly in DNA/RNA extraction procedures. The cationic nature of CTAB is important for its interactions with the negatively charged components of cells, contributing to its ability to solubilize and release cellular contents.
The hydrophobic tail of CTAB interacts with the hydrophobic regions of the cell membrane, disrupting its structure. The positively charged (cationic) head of CTAB interacts with negatively charged components on the cell surface, further destabilizing the membrane. This disruption of the cell membrane is referred to as cell lysis.
CTAB Buffers
the CTAB components are very slightly differ from various DNA/RNA extraction procedures, but here are some common components of CTAB Buffers:
CTAB
this is one of the main components that acts as a detergent which contains a hydrophilic head and hydrophobic tail that help to degrade the lysis of the cell membrane and release the components.
Typically, the concentration of CTAB in a CTAB buffer for DNA/RNA extraction from plant tissues ranges from 2% to 5% (w/v). However, it’s important to note that the exact concentration may differ based on the protocol or kit instructions
Tris-HCl
- this is another important component that helps to maintain the suitable pH in the solution.
- this buffer component that helps maintain a stable pH in the solution.
EDTA
EDTA is included in the buffer solution for DNA/RNA extraction as a chelating agent to sequester divalent cations, which, if present, could interfere with enzymatic reactions and compromise the integrity of samples. Its ability to inhibit metal-dependent enzymes, particularly nucleases, is essential for successful DNA/RNA extraction and subsequent molecular biology experiments.
β-Mercaptoethanol or Dithiothreitol (DTT)
These reagents help to break the disulfide bonds of the protein, a step that contributes to the overall disruption of cellular structures during extraction.
NaCl (Sodium Chloride)
another important reagent is Sodium chloride which helps to adjust the ionic strength to the solution. NaCl helps to remove cellular debris and other contamination in the solution and helps to get purified nucleic acid.
PVP (Polyvinylpyrrolidone)
PVP is one of the reagents sometimes used in CTAB Buffers which can help to remove polyphenols that can interfere with nucleic acid isolation.
