Overview:

• EDTA (Ethylenediaminetetraacetic acid) is a chelating agent. Due to its ability to sequester metal ions such as Mn²⁺, Ca²⁺, Mg²⁺ and Fe³⁺, EDTA is widely used in number of cell and molecular biology experiments.
• Metal ions are necessary for the activity of many enzymes (e.g., DNases and DNA modifying enzymes) as well as interactions of biomolecules (e.g., receptor-ligand interaction). Sequestration of metal ions disrupts metal ion-dependent interactions (e.g., cell-cell and cell substratum interaction) as well as inhibits the action of metal ion dependent enzymes.
• Here we describe steps to prepare 1 mM EDTA solution from stock EDTA solution.

Requirement

• Reagents
  • 0.5 M EDTA solution, pH 8.0 at 25°C
  • Deionized / Milli-Q water
• Equipment and disposables
  • Measuring cylinder

Composition:

1 mM  EDTA, pH 8.0 at 25°C

Objective:

Preparation of 100 ml of 1 mM EDTA solution (pH 8.0) from 0.5 M EDTA solution (pH 8.0)

Preparation:

You need to add 0.2 ml of 0.5 M EDTA in 99.8 ml water to achieve 100 ml of 1 mm EDTA solution. (See calculation)

Step 2: Take ≈50 ml water in a measuring cylinder and add 0.2 ml of 0.5M EDTA in it.

Tips: To mix solution, you can cover the measuring cylinder with parafilm and mix the solution by inverting the measuring cylinder 3 – 4 times. Take care no solution leaks out during this process. Alternatively, you can transfer solution to storage bottle and mix solution by swirling the bottle or using magnetic stirrer.

Storage:

Transfer solution to a storage bottle. You can store the solution at room temperature. Solution is stable at room temperature for long time.