Dear Elif,

If you keep the ammonium bicarbonate refrigerated and if you are performing many analysis and using up the solution regularly, you do not have to make it up fresh each time.

I make a 100 or 200 mM Ammonium Bicarbonate and make dilutions of this buffer when I need to have diluted buffer for destaining or digestions.  Everytihing is refrigerated and should be fine, especially if you are using the solutions up regularly.

Best,

Hediye

Hello Elif,

For regular in gel digestion, we keep concentrated stocks of Ambic (ammonium bicarbonate) and DTT (1 M) in the freezer (-20 C) for months; but IAA  (iodoacetamyde) solution is prepared fresh everytime needed. We also stock trypsin (0.1 ug/uL in 50 mM Acetic Acid), and then we dilute to 12.5 ng/uL in Ambic.

I hope it helps

Best,

Felix

Dear Elif, I always prepare the solution freshly with the exception of DTT that I keep at -20C. IAA must be prepared immediately before use and it is light sensitive. Trypsin should be kept at -20C and thawed immediately before use. Acetonitrile is volatile you may want to prepare freshly in order to be sure that you have the right concentration.

Hi Elif,

I think that I am missing out on this question.  I thought you were interested in AmBic only.  Here is our practice here:

We make up a stock solution of DTT at  10mM in AmBic and make aliquots so that they are one time used and discarded.  The stocks of DTT aliquots are kept at minus 20.

Iodoacetamide is made up fresh each time we use it.

Trypsin is reconstituted to 0.1 ug / ul and aliquoted into 10 and 20 ul aliquots.  These are kept at minus 80 and each tube is used only once.  We never freeze/thaw and then freeze  the aliquots of trypsin.

For desalting steps, the organic buffers are made up and kept at room temperature.  We use 0.1% formic acid to bind, wash the tip columns packed with C18 media.  The eluant, 40% acetonitrile in 0.1% formic acid is made up and also stored at room temperature.

Best,

Hediye.

Thank you all , it helps a lot :) God save Research Gate :D