0.1 M Phosphate Buffer pH 7.5
Definition
A 0.1 M phosphate buffer pH 7.5 is a solution used in molecular biology and biochemistry to maintain a stable pH and ionic strength. The solution is composed of a mixture of monobasic and dibasic sodium phosphate salts, which are dissolved in water to create a buffer solution.
Composition
A 0.1 M phosphate buffer pH 7.5 typically consists of:
- 0.1 M monobasic sodium phosphate (NaH2PO4)
- 0.1 M dibasic sodium phosphate (Na2HPO4)
- Water (H2O)
The exact composition of the buffer solution may vary depending on the specific application and the desired pH and ionic strength.
Preparation
To prepare a 0.1 M phosphate buffer pH 7.5, the following steps can be followed:
Step 1: Dissolve the Phosphate Salts
Dissolve 13.9 g of NaH2PO4 and 26.8 g of Na2HPO4 in 900 mL of water.
Step 2: Adjust the pH
Adjust the pH of the solution to 7.5 using a pH meter and HCl or NaOH as needed.
Step 3: Filter and Sterilize
Filter the solution through a 0.2 μm filter and sterilize it by autoclaving or filter sterilization.
Properties
The 0.1 M phosphate buffer pH 7.5 has the following properties:
- pH: 7.5
- Ionic strength: 0.1 M
- Osmolality: approximately 300 mOsm/kg
- Stability: stable at room temperature for several months
Applications
The 0.1 M phosphate buffer pH 7.5 is commonly used in various biomedical applications, including:
- Molecular biology: PCR, DNA sequencing, and gene expression analysis
- Biochemistry: enzyme assays, protein purification, and protein-protein interaction studies
- Cell culture: maintenance of cell cultures and cell-based assays
Note
It is essential to prepare the buffer solution accurately and maintain proper sterility to avoid contamination and ensure reliable results in experimental procedures.
