PBS Buffer Calculator, pH 7.4
Scale source-defined 1X and 10X phosphate-buffered saline recipes at pH 7.4 with exact phosphate reagent forms.
Select a reviewed preset and enter the final volume to prepare.
| Reagent | Formula | Amount or action |
|---|---|---|
| Sodium chlorideanhydrous | 8 g | |
| Potassium chlorideanhydrous | 200 mg | |
| Sodium phosphate dibasicanhydrous | 1.44 g | |
| Potassium phosphate monobasicanhydrous | 240 mg | |
| Purified water | After pH adjustment, bring the total solution volume to 1 L. Do not add 1 L of water; add water only until the total solution reaches 1 L. |
How to prepare 1X PBS pH 7.4
- Confirm the exact phosphate salts and hydration states shown for the 1X PBS pH 7.4 preset, including anhydrous sodium phosphate dibasic.
- Add the calculated salts to approximately 70–80% of the selected final volume of purified water.
- Stir until dissolved, then measure and adjust the pH to 7.4.
- Bring the total solution to the selected final volume, mix thoroughly, and verify the final pH.
About This Buffer
Phosphate-buffered saline (PBS) is a phosphate-buffered salt solution widely used for washing, dilution, and handling of biological samples and reagents. This calculator provides fixed 1X and 10X PBS formulations at pH 7.4. Each preset preserves the exact phosphate salt forms and pH workflow specified by its reviewed source.
Common questions
What is the difference between the 1X and 10X PBS presets?
The 10X preset contains tenfold-concentrated salts and is intended as a stock formulation. It also uses a specified dibasic phosphate hydration state that must not be silently substituted.
Why are phosphate hydration states important in PBS?
Hydrated and anhydrous salts have different molecular weights, so substituting one form without recalculating changes the composition.
Does this page calculate any arbitrary PBS strength?
No. It scales only the reviewed 1X and form-specific 10X presets by final volume.
Sources and review notes
The source for the currently selected preset appears first. Recipe quantities remain tied to the cited article location.
1X PBS pH 7.4
Source location: Materials, Buffers — 1X PBS salt formulation; dissolve in 800 mL, adjust to pH 7.4, then bring to 1 L. The titrant is not identified.
Preparation method: Source-stated quantitative composition
- Detecting reactive oxygen species by immunohistochemistry PMC4571457 · open article
View sources for all presets
10X PBS pH 7.4
Source location: Recipes, 10× phosphate buffered saline — exact dihydrate formulation; dissolve in 800 mL, adjust to pH 7.4, then bring to 1 L. The titrant is not identified.
Preparation method: Source-stated quantitative composition