Sep 26, 2022

Preparation of 0.5L of phosphate buffer (pH=6.0)

  • 1Research Centre on Animal Cognition (CRCA), Centre for Integrative Biology (CBI), Toulouse III University, CNRS, Toulouse, France
  • Perez-Escudero Lab
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Protocol CitationAlfonso Pérez Escudero, Alid Al-Asmar, gabrielmadirolas 2022. Preparation of 0.5L of phosphate buffer (pH=6.0). protocols.io https://dx.doi.org/10.17504/protocols.io.n2bvj8r7bgk5/v1
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: September 19, 2022
Last Modified: September 26, 2022
Protocol  Integer ID: 70215
Keywords: phosphate buffer, preparation of worm media, worm media, nematode growth medium, preparation, original source of the protocol
Abstract
Original source of the protocol: WormBook Methods http://www.wormbook.org/chapters/www_strainmaintain/strainmaintain.html
This protocol is for making pH=6.0 phosphate buffer, which is used in the preparation of worm media, like NGM (Nematode Growth Medium).
Materials
Monopotassium phosphate: Potassium phosphate monobasicMerck MilliporeSigma (Sigma-Aldrich)Catalog #795488-500G
Dipotassium phosphate: Potassium phosphate dibasicMerck MilliporeSigma (Sigma-Aldrich)Catalog #P3786-500G
Filter: Rapid-Flow Nalgene 0.2µm aPES membrane, ref: 564-0020
Vaccum pump: Fisher Brand, ref: FB70155
Add 54.2 g ±0.5 of monopotassium phosphate1 (KH2PO4) to a clean 0.5L bottle.

1Also referred to as potassium phosphate monobasic
Add 17.8 g ±0.2 of dipotassium phosphate2 (K2HPO4) to the bottle.

2Also referred to as potassium phosphate dibasic
Measure 500 mL of milliQ water in a measuring cylinder, and add it to the bottle.

Shake the bottle vigorously until all crystals are dissolved. This can take a few minutes.
If this is the first time you prepare this solution, you can ensure that the pH is around 6 using pH paper or a pH-meter. We usually have a pH between 5.8 and 6.
Filter-sterilize.
Store on shelf.
We usually use it without problem for at least a year after preparation.