Balanced Salt Solutions: Preparing Solutions from Powder Concentrates

Procedure F: Liquid Media: Prepare 1X Solutions from 10X Concentrates

To prepare an acceptable, final 1X solution, perform the following procedure under aseptic conditions. Use Distilled Water (Cat. no. 15230) and 7.5% Sodium Bicarbonate Solution Cat. no. 25080) for use in this protocol. Also note, because we adjust the pH of all 10X media and 10X balanced salt solution concentrates for solubility, you may need to adjust the pH after the dilution and to add sodium bicarbonate, as appropriate.

  1. Aseptically dilute 100 mL of 10X concentrate with approximately 850 mL of distilled water.
  2. Aseptically add the correct amount of 7.5% sodium bicarbonate solution. See Table 4 for concentrations.
  3. Adjust the pH as necessary with 1 N HCl or 1 N NaOH.
  4. Adjust the final volume with distilled water.
  5. Dispense the solution into sterile containers. Cap the bottles tightly with sterile closures and store at the recommended temperature (see product label).

Table 4: pH of the Medium after Dilution and Addition of 7.5% Sodium Bicarbonate Solution (Cat. no. 25080)

Balanced Salt Solutions

Cat. no.*  
pH of
10X soln
mL/L 7.5% soln
pH after 1:10
dilution &
     pH of 1X solna               
a: pH range varies depending on the pH of water used in dilution.

Procedure G: Prepare 1X Dulbecco’s Phosphate Buffered Saline from Powder (Cat. no. 21300*, 21600*)

  1. To a mixing container that is as close to the final volume as possible, add 950 mL of distilled water.
  2. Add powdered medium to room temperature (15°C to 30°C) water with gentle stirring.
  3. Rinse the inside of package to remove all traces of powder.
  4. If calcium chloride is included separately with the medium, add 0.1 g calcium chloride/L of medium.
  5. Adjust the final volume with distilled water.
  6. Process the medium immediately into sterile containers by membrane filtration with a 0.2-μm filter using a positive pressure system.

*For in vitro diagnostic use. Caution: Not for human or animal therapeutic use.