EDTA (Ethylenediaminetetraacetic acid) also known as Editic acid. EDTA is one of the most used chelating agents.
Chelating agents are chemical compounds (small molecules and peptides) which bind to metal ions and make them unavailable for other molecules/reactions. You can consider them as molecular prisons for ions. So, the ions are present in the solution but virtually absent like Joseph Cooper (Interstellar 2014) struck in another dimension.
EDTA sequesters metal ions such as Ca2+ and Fe3+. EDTA is commercially available in several forms.
Here are few
- EDTA (Molecular Weight: 292.24)
- EDTA.4Na.4H₂O (Molecular Weight: 452.23)
- EDTA.2Na.2H₂O ( Molecular Weight: 372.24)
- EDTA.2K.2H₂O (Molecular Weight:404.45)
Disodium EDTA dihydrate is common used form in biology laboratories.
- A variant of EDTA (Sodium Calcium EDTA) is used to treat lead (Pb) and mercury (Hg) poisoning.
- Used in dental procedures to remove inorganic depositions and calcification inside the root canal.
- Used to enhance the activity of preservatives in medical formulations.
- Used to remove limescale.
- Used as a preservative in processed foods and cosmetic products.
- Component of TAE, TBE, DNA loading dye, Tris-EDTA, Trypsin-EDTA.
- EDTA is used to enhance or diminish the activity of enzymes.
Example for reduced activity:
DNA polymerases require Mg2+ for their activity. Presence of EDTA in the solution results in sequestering of Mg2+. This eventually makes Mg2+ unavailable for DNA polymerase and thereby reduces its activity. Chelating property of EDTA is an advantage while isolation of DNA (to reduce DNase activity to prevent DNA degradation) whereas disadvantage in PCR (DNA polymerase activity is needed).
Example for enhanced activity:
Trypsin-EDTA is used for the preparation of single-cell suspension (dislodging the plated cells) from adherent cell culture by breaking the intercellular matrix. Calcium and magnesium ions enhance cell to cell adhesion. Presence of EDTA in the Trypsin mix, sequester the ions that strengthen the matrix. Trapping of these ions weaken the interactions and facilitates trypsin digestion.
For most applications, EDTA.2Na.2H2O solution pH 8.0 is used. EDTA solubility at neutral pH is very low, hence pH of the solvent (H2O) must be raised to 8 in order to increase solubility.
For making 0.5M EDTA.2Na.2H2O solution, you need approximately 20g of NaOH. You can either add NaOH in the form of pellets or 10N NaOH solution. In case of pH overshoot use HCl.
|Concentration||100 ml||250 ml||500 ml||1000 ml|
|100 mM||3.72 g||9.30 g||18.61 g||37.22 g|
|0.25 M||9.31 g||23.26 g||46.53 g||93.06 g|
|0.5 M||18.61 g||46.53 g||93.06 g||186.12 g|
- NaOH pallet / 10N NaOH solution (for pH adjustment)
- Deionized / Milli-Q water
Instruments and other requirements
- Measuring cylinder
- Conical flask / Beaker
- Magnetic stirrer
- pH meter
- Paper towels
- Take the 20% less volume of solvent than planned. E.g., if you want to make 1L of the solution, take 800ml.
- Add EDTA.2Na. 2H2O (see the table).
- Keep the beaker on the magnetic stirrer with magnetic pellet. Keep the pH probe to monitor pH.
- Add 75% of NaOH pellets (calculate the rough amount based on 20g/L for making 0.5M).
- Allow the NaOH to dissolve completely. Check the solubilization of disodium EDTA dihydrate as well.
- Add rest of the NaOH pellets one by one. Do not get tempted to add vast amounts at once. You may overshoot the pH.
- Once the EDTA dissolves completely, check for the pH. Use HCl if needed.
- Transfer the solution into the graduated cylinder and adjust the volume.
- Sterilize by Filter sterilization (0.22 micron) or by autoclaving.
Edta – Uses, Side Effects, and More
Why do people take EDTA?
EDTA is sometimes prescribed by doctors to clean toxic metals, such as lead, from the blood. Doctors have used the molecule for decades to treat heavy metal poisoning. In those cases it is given through an IV.
EDTA is also an ingredient in some prescription cancer-fighting medicines.
Supplement makers claim that over-the-counter forms of EDTA can be taken by mouth to “detox” the body and make your gastrointestinal tract healthier. There is no scientific evidence to support this.
Preliminary studies show that intravenous EDTA therapy under physician supervision may help patients who have had a heart attack, particularly if they have diabetes. However, more study is needed to prove this.
Some people take EDTA to try to treat:
- Peripheral vascular disease
- Alzheimer’s disease
- Heart disease
Can you get EDTA naturally from foods?
EDTA is a chemical that is added to certain foods and beverages to help them keep their color and flavor. For instance, it is sometimes added to:
- Canned fruits and vegetables
- Non-nutritive sweeteners
- Condiments such as mayonnaise
- Salad dressings
The FDA says EDTA is considered safe for use in foods in the U.S.
What are the risks of taking EDTA?
The most common side effect of EDTA is burning at the IV site.
Chelating agents can also have serious, even life-threatening side effects. One of the most serious side effects of EDTA is kidney damage and kidney failure.
Other side effects that have been reported in patients taking some forms of EDTA have included:
- Chills, fever, or headache
- Blood clot in a vein
- Lower levels of magnesium and potassium in the blood
- Diarrhea, vomiting, or nausea
- Abnormal calcium levels in the blood
- Insulin shock
- Irregular heartbeats, which can be severe
- Low blood pressure
- Aching joints
- Coumadin (warfarin)
EDTA can also interact with diuretics (water pills). It may lead to dangerously low potassium levels. This can cause severe, irregular heartbeats. Make sure your doctor knows if you are taking any of these medicines.
Talk to your doctor before taking EDTA if you take any medicines or have any medical conditions:
- Heart problems
- Kidney disease
- Liver disease, including hepatitis
- Low levels of calcium, magnesium, or potassium
- Seizure disorders
Always tell your doctor about any medicines and supplements you are taking, including natural ones and those bought without a prescription. That way, your doctor can check on any potential side effects or interactions with any of your medicines or health conditions.
Supplements are not regulated by the FDA the same way that medicines are. They are treated as foods and do not have to prove that they are safe or effective before being sold on the market.
How does it work?
EDTA is a chemical that binds and holds on to (chelates) minerals and metals such as chromium, iron, lead, mercury, copper, aluminum, nickel, zinc, calcium, cobalt, manganese, and magnesium. When they are bound, they can’t have any effects on the body and they are removed from the body.
Uses & Effectiveness
- Treating lead poisoning. Administering EDTA intravenously and intramuscularly is effective for treating lead poisoning and brain damage caused by lead exposure. The calcium disodium form of EDTA is approved by the U.S. Food and Drug Administration (FDA) for these uses. Treatment with calcium disodium EDTA improves symptoms of lead poisoning such as abdominal pain, fatigue, constipation, and loss of appetite. It also seems to slow progression of kidney failure in patients who have had long-term lead poisoning. However, EDTA does not seem to be effective for diagnosing lead poisoning.
Likely Effective for…
- Emergency treatment of life-threatening high calcium levels (hypercalcemia), when given intravenously. The disodium form of EDTA is approved by the FDA for this use, but healthcare providers generally prefer other methods of treatment that are less likely to cause kidney side effects.
- Treating heart rhythm problems caused by drugs such as digoxin (Lanoxin). The disodium form of EDTA is approved by the FDA for this use, but healthcare providers generally prefer other treatments such as lidocaine or phenytoin (Dilantin) because they are considered safer and more effective.
Possibly Effective for…
- Treating calcium deposits in the eye. After appropriate preparation of the eye, a single application of the disodium form of EDTA can clear calcium deposits in the eye and improve eyesight.
Possibly Ineffective for…
- Hardened skin (scleroderma).
Likely Ineffective for…
- Treating coronary heart disease (CHD).
- Treating peripheral arterial occlusive disease.
Insufficient Evidence to Rate Effectiveness for…
- Poisoning by radioactive products.
- Wilson’s disease.
- Atherosclerosis (hardening of the arteries).
- High cholesterol.
- High blood pressure.
- Raynaud’s syndrome.
- Vision problems.
- Alzheimer’s disease.
- Multiple sclerosis.
- Parkinson’s disease.
- Chest pain (angina).
- Other conditions.
More evidence is needed to rate the effectiveness of EDTA for these uses.
Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, and Insufficient Evidence to Rate (detailed description of each of the ratings).
EDTA is safe when used as a prescription medicine, as eye drops, and in small amounts as a preservative in foods. EDTA can cause abdominal cramps, nausea, vomiting, diarrhea, headache, low blood pressure, skin problems, and fever.
It is UNSAFE to use more than 3 grams of EDTA per day, or to take it longer than 5 to 7 days. Too much can cause kidney damage, dangerously low calcium levels, and death.
Special Precautions & Warnings:
Pregnancy and breast-feeding: EDTA seems to be safe when used in food amounts. The safety of larger amounts is unknown.
Asthma: Nebulizer solutions containing disodium EDTA as a preservative can cause the breathing tubes to narrow in some people with asthma. The size of the dose determines the amount of the narrowing.
Heart rhythm problems: EDTA might make heart rhythm problems worse.
Diabetes: EDTA might interfere with blood sugar control because it can interact with insulin.
Low calcium levels in the blood (hypocalcemia): EDTA can decrease serum calcium levels, making hypocalcemia worse.
Low potassium (hypokalemia): EDTA can bind with potassium and increase the amount of potassium that is flushed out in the urine. This might cause potassium levels to drop too low, especially in people who have low levels to begin with. If you have this problem, don’t use EDTA.
Low magnesium levels in the blood (hypomagnesemia): EDTA can bind with magnesium and increase the amount of magnesium that is flushed out in the urine. This might cause magnesium levels to drop too low, especially in people who have low levels to begin with. If you have this problem, don’t use EDTA.
Liver problems and hepatitis: EDTA might make liver disease worse. Avoid using EDTA if you have a liver condition.
Kidney problems: EDTA can harm the kidney and might make kidney disease worse. EDTA doses should be reduced in patients with kidney disease. Avoid using EDTA if you have severe kidney disease or kidney failure.
Seizures (epilepsy): There is some concern that EDTA might increase the risk of seizure in people with epilepsy or in people who tend to have seizures. EDTA can cause severe decreases in blood levels of calcium, and this can cause a seizure.
Tuberculosis (TB): Tuberculosis is a lung infection that is caused by particular bacteria. Sometimes the body is able to “wall off” pockets of infection, making the infection inactive. The bacteria remain alive behind the wall of scar tissue, but they can’t get out to cause illness or infect other people. This scar tissue frequently contains calcium. There is some concern that EDTA might be able to bind the calcium in the scar tissue, causing the “walls” to give way and release bacteria. Don’t use EDTA if you have active TB or had TB in the past.
InsulinInteraction Rating: Major Do not take this combination.EDTA can decrease blood sugar. Insulin is also used to decrease blood sugar. Taking EDTA along with insulin can cause serious decreases in your blood sugar. Monitor your blood sugar closely. The dose of your insulin might need to be changed.
Warfarin (Coumadin)Interaction Rating: Major Do not take this combination.Warfarin (Coumadin) is used to slow blood clotting. EDTA has been reported to decrease the effectiveness of warfarin (Coumadin). Decreasing the effectiveness of warfarin (Coumadin) might increase the risk of clotting. It is unclear why this interaction might occur. Be sure to have your blood checked regularly. The dose of your warfarin (Coumadin) might need to be changed.
Water pills (Diuretic drugs)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.Large amounts of EDTA can decrease potassium levels in the body. “Water pills” can also decrease potassium in the body. Taking EDTA along with “water pills” might decrease potassium in the body too much.
Some “water pills” that can deplete potassium include chlorothiazide (Diuril), chlorthalidone (Thalitone), furosemide (Lasix), hydrochlorothiazide (HCTZ, HydroDiuril, Microzide), and others.
The following doses have been studied in scientific research:
APPLIED TO THE SKIN:
- For calcium deposits on the cornea of the eye: Healthcare providers use EDTA as part of a procedure.
- For lead poisoning and also for high levels of calcium in the blood: Healthcare providers give EDTA intravenously (by IV).
- For lead poisoning: Healthcare providers give EDTA in a shot (by injection).