Citrate-Phosphate Buffer (110 mM, pH 5.6) Preparation and Recipe

A traditional buffer originally introduced in 1921. Since the Citrate-Phosphate buffer (also known as the McIlvaine buffer) only has 2 ingredients, the recipe can be adjusted to a pH range of 3-8. It is used for multiple applications in cell biology, molecular biology, and hematology.

To prepare

L of Citrate-Phosphate Buffer (110 mM, pH 5.6):

Change the value in the textbox above to scale the recipe volume

Table 1. Required components

Component	Amount	Concentration
Sodium phosphate dibasic (anhydrous) (mw: 141.96 g / mol)	#	#
Citric Acid (mw: 192.12 g / mol)	#	#

Prepare 800 mL of distilled water in a suitable container.
Add # of Sodium phosphate dibasic (anhydrous) to the solution
Add # of Citric Acid to the solution
Add distilled water until the volume is 1 L.
Sterilize by autoclaving. (The final solution contains 50 mM Na2HPO4.)

References

This online resource may be cited as follows

MLA	"Quest Calculate™ Citrate-Phosphate Buffer (110 mM, pH 5.6) Preparation and Recipe." AAT Bioquest, Inc., 27 Oct. 2025, https://www.aatbio.com/resources/buffer-preparations-and-recipes/citrate-phosphate-buffer-110-mm-ph-5-6.
APA	AAT Bioquest, Inc. (2025, October 27). Quest Calculate™ Citrate-Phosphate Buffer (110 mM, pH 5.6) Preparation and Recipe. AAT Bioquest. https://www.aatbio.com/resources/buffer-preparations-and-recipes/citrate-phosphate-buffer-110-mm-ph-5-6.
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