At 11:44 AM 24/02/97 +0000, Arnold Pizzey wrote: > I would question the efficacy of using 70% ETOH alone as a >sterilization agent specifically in flow as well as generally in the >laboratory. Although ETOH has some bactericidal activity against common >water-borne contaminants such as the pseudomonads and the like I would >imagine that most airborne contaminants that float into the sheath tank >would be of the Gram-positive persuasion and as such quite resistant to the >effect of ETOH. This is a very useful & timely warning for people like me with mechanical/engineering background rather than lab/biology trained. I've always been led to believe that 70% ETOH will knock off anything of interest in this context. Anyone else (microbiology types?) like to comment? > As for swabbing down external surfaces with 70% ETOH, I would > regard this as an excellent strategy for mobilizing bacterial aerosol. Could you please expand on this Arnold? Maybe we're not talking the same language; To me, "swabbing down" means "take some material (paper towel, tissue etc), douse it with some solvent (70% ETOH) and wipe the area or object to be cleaned with the solvent-wet material." This to me specifically excludes splashing or spraying, and I'm not able to equate this activity with creating or mobilising any aerosol. >On the few occasions when I have had to carry out sterile sorting, my >strategy is as follows: > > Clean sort nozzle/flow cell /sheath tank with a proprietary detergent and >rinse in sterile H2O. > Wash the sort collection area down with a proprietary detergent > Bypass the in-line sheath filter, Then flush system with following: > 1)H2O > 2)Surface active agent e.g. 0.1% DECON 90 > 3)Sterile H20 > 4)Sterile sheath fluid > 5)Fit new sterile in-line sheath filter. Maybe I'm missing something (as I often do!) but you have not included anything that I recognise as a sterilising agent. Which of these steps is intended to kill pre-existing bugs? Many thanks for your tolerance of my ignorance, this old dog would like to learn some new tricks. Regards, Joseph. -- Joseph Webster Flow Cytometry Facility Centenary Institute
This archive was generated by hypermail 2b29 : Wed Apr 03 2002 - 11:49:26 EST