antibiotics at room temperature
Posted 13 March 2009 - 10:57 AM
I did a stupid mistake, and realized it later. We usually store Ampicillin and Kanamycin antibiotic solutions (50mg/ml) at 20 degree C. But somehow after using those antibiotics , I left them at room temperature(25/26 degree C) for 2/3 days . After realizing the mistake I quickly put them back in -20 degreeC. Will they be fine , or I have to prepare new ones?
Posted 13 March 2009 - 11:28 AM
Posted 13 March 2009 - 01:56 PM
Posted 15 March 2009 - 02:35 AM
Posted 15 March 2009 - 03:28 PM
Posted 16 March 2009 - 12:27 PM
Posted 16 March 2009 - 03:46 PM
Posted 16 March 2009 - 06:00 PM
Certainly there is some degradation. But does it matter in this situation? The amount of ampicilin used in a selection plate for cloning purposes varies from 100ug/ml to 25ug/ml. My lab uses 25ug/ml but I have seen labs use 100ug/ml
So, if you assume degradation of the antibiotic I would use 50ug/ml or 100ug/ml which would give me more than enough antibiotic for selection.
I feel it is such a waste to dump a vial of antibiotic stock solution, when the finally concentration of the antibiotic isn't important.
Posted 17 March 2009 - 01:59 AM
Do you run a test plate when you make up your antibiotics? You could run a plate to test the efficiency of your experimental dose. (Not that I ever did a test plate on each antibiotic batch I made up. Does anyone else?).
Posted 17 March 2009 - 03:00 AM
Posted 17 March 2009 - 05:35 PM
I personally would toss the antibiotic and make a fresh stock because most of the time, the antibiotic comes into play after I've performed many laborious steps leading up to selection, and I'd rather waste some antibiotic then all that labor.