Buffer recipes

Published on Author Anne Petzold

Some general stuff

For a reminder on how to calculate the volumes you need for the product you want to make, see, e.g., here: http://abacus.bates.edu/~ganderso/biology/resources/dilutions.html.

If your buffer is based on powdered ingredients, add the powder first and add water up to your desired volume.

Put your buffer in glass bottles to autoclave later (there is a small autoclave in the lab). We also have Anachem filters (pore size 0.2 um) or syringes with filters (for small volumes) to pour through.

1 M Tris-HCl @ pH 8.0, 600 ml

1 M TrisHCl alone has a pH around 4 and 1 M Tris Base alone has a pH around 11 (and HCl a pH around 2), so both need to be combined to obtain a pH of 8.0, e.g., 40% Tris Base and 60% TrisHCl.

See a mixing table here for 0.05 M solution: http://www4.mpbio.com/ecom/docs/proddata.nsf/%28webtds2%29/103132.

Recipe

For 1 M TrisHCl (FW=157.6), weigh 37.82 g of TrisHCl and stirr together with ddH2O until a total volume of 230 ml.

For 1 M Tris Base (FW=121.4), weigh 43.704 g of TrisHCl and stirr together with ddH2O up to a final volume of 350 ml.

Mix and check pH. Adjust pH with HCl and add ddH2O to reach 600 ml.

0.5 M EDTA @ pH 8.0, 500 ml Stock solution (FW=372.2)

Ingredients

93.05 g Na2.EDTA (Disodium EDTA)

~10 g NaOH (FW=40) to adjust pH (pellets)

500 ml ddH2O

Recipe

EDTA dissolves reluctantly, so pour around 350 ml ddH2O in a flask and add EDTA incrementally while stirring vigorously with magnetic stirrer. Mix around 9 g of NaOH with 50 ml of ddH2O in a beaker or flask. When both solutions are dissolved, add NaOH to EDTA. Measure pH while stirring. Adjust pH to 8.0 with NaOH.

see http://bioinfoweb.com/Protocol-preparation-of-0.5M-EDTA-stock-solution.htm for even more instructions and a mixing table

10 x TE (Tris EDTA) @ pH 8.0, 100 ml

Recipe

Pour 88 ml of ddH2O in a beaker or flask, add 10 ml of 1 M Tris-HCl and 2 ml of 0.5 M EDTA. Check pH.

extensive information and a mixing table @ http://bioinfoweb.com/Protocol-preparation-of-100ml-10X-tris-EDTA-pH-8.0-solution.htm

For a 1 x solution, use 1 part 10 x TE and 9 parts ddH2O.