Jun 03, 2020
Citrate Buffer
- 1University of Manitoba
Protocol Citation: Neilier Junior 2020. Citrate Buffer. protocols.io https://dx.doi.org/10.17504/protocols.io.bfyfjptn
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
We use this protocol and it's working
Created: May 05, 2020
Last Modified: June 03, 2020
Protocol Integer ID: 36583
Keywords: pH, Henderson-Hasselback, Biochemistry, Molecular Biology,
Abstract
A buffer solution has the function of resisting changes in pH even when adding powerful acids or bases. However, in the physiological environment the buffered system also provides cofactors for enzymatic reactions, critical salts and even essential nutrients for cells and tissues. Therefore, when trying to reproduce biological conditions in vitro, we must make the appropriate choice of the buffer. After all, it will provide the appropriate medium in which reactions will occur.
Materials
- Deionized Water
- pH Meter (sensitive)
- Citric Acid
- Sodium Citrate Dihydrate
Safety warnings
Wear personal protective equipment: gloves, lab coat and mask.
Before start
Organize your workspace.
Make sure all solutions and equipment are available.
Citrate Buffer
Citrate Buffer
Note
pH range: 3.0 to 6.2
(a) 0.1 M Citric acid: 19.21 g L-1 (M.W.: 192.1 g mol-1)
(b) 0.1 M Sodium citrate dihydrate: 29.4 g/l (M.W.: 294.0 g mol-1)
Mix citric acid and sodium citrate solutions in the proportions indicated and adjust the final volume to 100 mL with deionized water.
| mL of Citric acid | 46.5 | 40.0 | 35.0 | 31.5 | 25.5 | 20.5 | 16.0 | 11.8 | 7.2 | |
| mL of Sodium citrate | 3.5 | 10 | 15.0 | 18.5 | 24.5 | 29.5 | 34.0 | 38.2 | 42.8 | |
| pH | 3.0 | 3.4 | 3.8 | 4.2 | 4.6 | 5.0 | 5.4 | 5.8 | 6.2 |
Adjust the final pH using a sensitive pH meter.
Note
The use of pentahydrate salt of sodium citrate is not recommended.