QS - (Feb/06/2014 )

Hello, everyone.

A friend and I were discussing the term 'quantum sufficit' or (incorrectly) 'quantum sufficient'.  We understand it to mean adding water to a concentrated stock solution in order to make sufficient working stock; e.g. when making 1.0 L of LB media, you do not add the necessary reagents to 1.0 L of water and mix, you would add it to, say, 750mL of water, mix and pH the solution, then add enough water to get up to 1.0 L.

Does anybody else use the term 'QS'?  I mentioned it today to some coworkers and nobody knew what it meant.

Thanks for your opinions!

I use it as an abbreviation in my lab book - I use it as you do - "make up to final volume"  and have never considered that it might have any other meaning.

I have seen it on medicines actually.  Didn't quite know what it meant, until today.

Thanks, LabLackey! 

I use QS when I'm writing protocols. I picked it up at a pharmaceutical company I used to work at, although I seem to recall my old grad school PI using it, too.

i've seen it used in papers and instructions.