Ethylene Diamine Tetraacetic Acid (EDTA) is an important complex agent. EDTA has a wide range of uses, can be used as a bleaching fixing solution for color sensitive materials washing processing, dyeing AIDS, fiber treatment AIDS, cosmetic additives, blood anticoagulant, detergent, stabilizer, synthetic rubber polymerization initiator, EDTA is a representative substance of chelating agent. It can form stable water-soluble complexes with alkali metals, rare earth elements and transition metals. In addition to sodium salts, there are ammonium salts and iron, magnesium, calcium, copper, manganese, zinc, cobalt, aluminum and other salts, which have different uses. In addition, EDTA can also be used to make harmful radioactive metals quickly excreted from the body to play a detoxification role. EDTA is also an important indicator, but used to titrate metal nickel, copper, etc., when used with ammonia, in order to play the role of indicator.
Basic structure of EDTA
EDTA, with the chemical formula C10H16N2O8, is a colorless or white powdery compound first synthesized by Ferdinand in 1935. It is known for its potent chelation and ability to form stable coordination complexes with a wide range of metal ions.
The EDTA molecule contains 6 individual electron pairs (two nitrogen atoms and four oxygen atoms) that can form strong coordination bonds with metal ions, especially divalent and trivalent metal ions, effectively “locking” the metal ions from solution, preventing them from participating in unwanted chemical reactions.
Table 1 EDTA and related products at BOC Sciences.
| Catalog | Product Name | CAS Number | Category |
| 60-00-4 | Ethylenediaminetetraacetic acid | 60-00-4 | Pharmaceutical Excipients |
| 139-33-3 | Ethylenediaminetetraacetic acid disodium salt | 139-33-3 | Pharmaceutical Excipients |
| 15251-22-6 | Ethylenediaminetetraacetic acid-[d4] | 15251-22-6 | Stable Isotope Labelled Compounds |
| 15375-84-5 | Manganese disodium EDTA trihydrate | 15375-84-5 | Pharmaceutical Excipients |
| 203805-96-3 | EDTA-[d16] | 203805-96-3 | Stable Isotope Labelled Compounds |
| 203806-08-0 | Ethylenediaminetetraacetic acid-[d12] | 203806-08-0 | Stable Isotope Labelled Compounds |
| 25102-12-9 | EDTA-2K Dihydrate | 25102-12-9 | Chemiluminescent Substrates |
| 470462-56-7 | Ethylenediamine-N,N,N’,N’-tetraacetic Acid-[13C4] | 470462-56-7 | Stable Isotope Labelled Compounds |
| 6381-92-6 | EDTA disodium salt dihydrate | 6381-92-6 | Pharmaceutical Excipients |
| 65501-24-8 | EDTA-3K Dihydrate | 65501-24-8 | Chemiluminescent Substrates |
Application of EDTA in experiments
Chelating metal ions
EDTA is an important chelating agent, which can form stable complexes with most metal ions (such as Mg2+, Ca2+, Mn2+, Fe2+, etc.). This capability makes EDTA very useful in determining the concentration of metal ions in water or in solution, and by forming complexes, it can prevent discoloration, deterioration, turbidity, etc., caused by metal ions, thereby improving the accuracy and reliability of the analysis.
Indicator action
EDTA can also be used as an indicator for titration of metal ions (e.g., nickel, copper, etc.), but it usually needs to be used in conjunction with ammonia, etc., to perform an indicative role.
Anticoagulant
EDTA salts (such as potassium salts, sodium salts, etc.) are commonly used blood anticoagulants and are widely used in clinical testing. EDTA effectively prevents blood clotting by forming a stable chelate with calcium ions in the aqueous phase, thereby maintaining the stability of blood samples during collection, transportation, and testing, ensuring the accuracy and reliability of test results. For example, EDTA anticoagulant blood collection tubes play an important role in routine blood testing, blood grouping, and ABO hemolysis testing.
Stabilizers in pharmaceutical formulations
EDTA can also be used as a stabilizer in pharmaceutical formulations, increasing the stability and solubility of the drug and ensuring the effectiveness of the drug during storage and use.
Removal of heavy metal ions in sewage
EDTA can remove heavy metals and other pollutants from industrial wastewater and improve water quality through complexation with metal ions. This capability makes EDTA an important application value in the field of water treatment.
Detergents
EDTA has chelating effect on metal ions such as iron, calcium, magnesium, etc., and can be used as a chelating agent in detergents and detergents. By reducing the influence of metal ions in the water on the washing effect, EDTA can prevent the formation of scale and stains, and improve the washing effect.
Other applications
Cell digestion: Since Ca2+ and Mg2+ are important components of the cell membrane and have the function of agglutinating cells, EDTA can disrupt the connections between cells and promote cell division into single cells. Therefore, EDTA also plays an important role in cell digestion processes where cell surface molecules need to be detected.
Food preservatives and antioxidants: EDTA can also be used as food preservatives and antioxidants to extend the shelf life of foods.
Material additives: EDTA can also be used as additives for trace element fertilizers to provide trace elements such as iron, zinc, and manganese required by plants.
Application of EDTA in molecular biology
Inhibition of enzyme activity
In molecular biology experiments, many enzymatic reactions require specific metal ions as cofactors. However, in some cases, in order to study the structure or function of enzymes, it is necessary to temporarily inhibit the activity of these enzymes. EDTA effectively inhibits the activity of enzymes by binding to these metal ions, preventing them from binding to enzymes. This property makes EDTA an important tool for studying enzyme structure and function.
Preservation and extraction of DNA and RNA
DNA and RNA are at the heart of molecular biology research. In order to maintain their stability and integrity, they need to be stored in an appropriate solution. EDTA is often used in the preparation of DNA and RNA preservation solutions because of its ability to chelate metal ions in solution and reduce the degradation of DNA and RNA by these ions. In addition, EDTA also helps to remove metal ions bound to nucleic acids during the extraction of DNA and RNA, improving the extraction efficiency.
Isolation and purification of plasmid DNA
Isolation and purification of plasmid DNA is a common and important step in molecular biology experiments. EDTA is widely used in the extraction of plasmid DNA as part of the buffer. By binding to metal ions in solution, EDTA helps to maintain the stability of the extraction environment and prevents metal ions from damaging plasmid DNA. At the same time, EDTA can also bind to certain cell wall components to promote cell lysis and plasmid DNA release.
PCR reactions
Polymerase chain reaction (PCR) is a commonly used method in molecular biology to amplify specific DNA fragments. In PCR reactions, the presence of metal ions may have an effect on the activity of the polymerase. In order to maintain the activity and stability of the polymerase, an appropriate amount of EDTA is usually added to the PCR reaction. EDTA ensures a smooth PCR reaction by binding to metal ions, reducing their effect on polymerase activity.
Composition of the running buffer
In electrophoresis experiments, buffers containing EDTA are often used in order to maintain the stability of the electric field and the separation effect. EDTA is able to chelate metal ions in solution, preventing them from unwanted interactions with charged molecules such as DNA or RNA, thus ensuring the accuracy and reliability of electrophoresis results.
Precautions for the use of EDTA
When using EDTA, special attention needs to be paid to the operation during the formulation process. First, EDTA was added to the PBS (pH 7.2) solution, then NaOH (equivalent solution) was added to facilitate dissolution, and finally 1 mol/L HCl was used to adjust to pH 7.2. Due to the long decalcification time, it is necessary to replace the new solution regularly to ensure the accuracy and stability of the experiment.