Cloudy NZY + Broth maybe contaminated??
Posted 28 July 2011 - 10:38 AM
10g NZ Amine (casein hydrolysate)
5 g yeast extract
5 g NaCL
add h20 up to 1 L, adjust pH to 7.5 with NaOH, and then autoclave.
Prior to use, I add filter sterilized in a hood:
12.5ml 1M MgCl2
12.5 ml of 1M MgSO4
10 ml of 2M glucose
I used it one time by opening quickly and taking what I needed and immediately resealing (all done in open air). A few days later I noticed that it was a little cloudy so I remade it exactly as described above, but this time when I aliquoted some I took it into the hood, sprayed everything with EtOH, had brand new gloves sprayed with EtOH and only had bottle open for 5 seconds. Again, about a day or two later I noticed it is cloudy again! Is this media very very very easy to contaminate, or is it some ingredient (maybe the glucose) that is making the liquid cloudy?? It's driving me a little crazy because I obviously cannot remake this every time I want to transform! Tonight, I will aliquot 5 mL into one falcon tube and shake 220RPM/37deg/overnight and a separate 5ml into another falcon tube which I will let sit on my lab bench. Tomorrow I will check to see if the one that I shook is more cloudy, which I would assume means that my stock is indeed contaminated?? Any help is appreciated, as always!
Posted 28 July 2011 - 04:00 PM
Posted 28 July 2011 - 04:11 PM
Posted 30 July 2011 - 08:28 PM
Posted 17 February 2012 - 02:46 AM
Could that cloudiness be from the NZ amine? Would it help to filter it before autoclaving? I'm bit affraid to use this one, it is for the mutagenesis kit.
I never trust anything that can't be doubted.