Hi Ravi,

It all depends on what type of buffer you are talking about. If the buffer does not contain any protein, such as a PBS buffer or Tris buffer and the like, these can be stored at room temperature for extended periods of time up to 2 years for as long as the room is sanitized/disinfected and the users of the buffer only take aliquot portions rather than inserting their pipets into the bottle. So, for these buffers and all kinds of buffers, the stock solution must not be exposed to possible sources of contamination. To do this, pour out the aliquot you need and never return unused portions to the stock bottle.

In the case of buffers with proteins, it is a different story. These buffers such as TBSA or PBS-BSA and the like, have a shelf-life that is shorter because these can be attacked by microorganisms that can thrive on the proteins. These must be refrigerated at all times. In the proper conditions, these can be stored for a maximum of 6 months if the stock bottles are not exposed to any possible source of contamination. As mentioned by other researchers above, you can add a preservative such as sodium azide as long as this does not interfere with your studies. You can establish the shelf-life of your own buffers by yourself too if you want. Having said all these, however, the best protein-containing buffers will be those that are freshly prepared because you know that there will be no possible contamination in them yet as long as you prepared them properly (using double deionized and organic-free water or autoclaved inorganic buffer prior to the addition of the protein). My advice is always make sure that your stock buffer does not get exposed to any pipets or other things that can introduce airborne-contaminants to the buffer. Hence, it is always best to pour out the aliquots from the stock bottle and never return unused portions to the stock bottle (or to the aliquot bottle).

Perfer to maintain in a cool temperature without freezing

Store the Buffer Between 4 to 12 Degree Centigrade,

Long time...you mean for above 6months to years? better to prepare fresh for your biochemical applications! I would say do not store more than a month, and dont dilute from a stock buffer.

As said, you can keep it at low temperature. You could also add chemicals such as sodium azide, if they do not interfere with your work.

Hello. From my experience: temp. 4-5C, darkness (so the lab cooler will be enough). The term of storage depends on concentration and substances diluted - some of them may precipitate in low temperature, other may react with other constituents or just oxidize. Filter sterilization, as Madhubrata Ghosh have mentioned, is necessary especially if you work on cell culture. For simple enzymatic analyses of crude extract you can prepare the stock for further dilution. It is less time-consuming that preparation de novo every time when needed.

depends. every buffer has shelf life. exceeding the time limit of any given buffer should be considered to get reproducible results.

If you look in the methods in enzymology volume 182or 184, I am not sure which one of them ,it contains a very useful information about this subject ,in fact this book contain one chapter deals with buffers

Try to avoid store your working buffer, use always freshly prepared buffer for better result......... Some people store their buffer at low temp for few days.

Dear Ravi

You cant store buffer for long time. It is better to prepare fresh buffer solution every times before analysis of sample. Filter buffer solution prior to analysis.

Dr. M.R Tiwari

Hi Ravi,

It all depends on what type of buffer you are talking about. If the buffer does not contain any protein, such as a PBS buffer or Tris buffer and the like, these can be stored at room temperature for extended periods of time up to 2 years for as long as the room is sanitized/disinfected and the users of the buffer only take aliquot portions rather than inserting their pipets into the bottle. So, for these buffers and all kinds of buffers, the stock solution must not be exposed to possible sources of contamination. To do this, pour out the aliquot you need and never return unused portions to the stock bottle.

In the case of buffers with proteins, it is a different story. These buffers such as TBSA or PBS-BSA and the like, have a shelf-life that is shorter because these can be attacked by microorganisms that can thrive on the proteins. These must be refrigerated at all times. In the proper conditions, these can be stored for a maximum of 6 months if the stock bottles are not exposed to any possible source of contamination. As mentioned by other researchers above, you can add a preservative such as sodium azide as long as this does not interfere with your studies. You can establish the shelf-life of your own buffers by yourself too if you want. Having said all these, however, the best protein-containing buffers will be those that are freshly prepared because you know that there will be no possible contamination in them yet as long as you prepared them properly (using double deionized and organic-free water or autoclaved inorganic buffer prior to the addition of the protein). My advice is always make sure that your stock buffer does not get exposed to any pipets or other things that can introduce airborne-contaminants to the buffer. Hence, it is always best to pour out the aliquots from the stock bottle and never return unused portions to the stock bottle (or to the aliquot bottle).

you can add also some sodium azide (0.01%) to the buffer but low molecular weight azides especially are considered hazardous and are avoided. Then, you should be carefully because is poisonous.

Really the best way is to store the buffer in the fridge...

Always make 10X or 5X stock, taking sterile precautions. For 1x, use Na N3 if not interfering with your system and store at 4 deg C.

Hi dear Ravi

All of suggestions are true.I prepared 5X solution with sodium azide (as antifungal) and put it on bottle. Then, I covered the bottle with aluminium foils and keep in refrigrator. This may be use until finish.

Cheers