Sterile sorting - Summary (one more)

I always refer to this as aseptic sorting since it can't be truely 
strile unless the instrument is kept in a hood. Regardless I have had 
user sort and keep cells in longtem culture with no anibiotics with 
success.
I have two small tanks that I have setup with no 0.2um filter one w/ 
EtOH the other with detergent. Every morning I disconnect the pressure 
and supply line from the sheath tank and run 70% EtOH through the back 
of the instrument for 15 minutes alternating between run and fill 
several times and purging the syring port ( this is assuming that you 
are using a Vantage) If not basically make sure the EtOH make it through 
all fluid lines.
Next, run Coulter Clenz or Contrad or FACSRinse through the same way as 
the EtOH. If you find that you are getting bubbles from the detergent 
briefely go back to EtOH before returning to the Sheath. Make sure to 
wear gloves and spray the connectors w/ EtOH when switching between 
tanks. I then run 10% Bleach, detergent, EtOH and finally sterile 
filterd dH2O through the sample line for ~10 min each. It is also a good 
idea to set up cultures of your sheath collected from the nozzle and the 
sample line to diagose if your sheath is contaminated.
I use a sheath that it shipped to me in 20L Boxes that is sterile, 
microplamsa and endotoxin free. I transfere it as aspeptically as 
possible through the supplied strile tubing and a quick connect into 20L 
sheath tanks that have been washed and autoclaved. I install a new 0.2um 
filter to each tank and keep at least one spare tank prepared.
Using this method I have had virtually no contamination and when I have 
had it it is usually introduce not from the sheath but the growth madia 
or the sample and occasionally from poor aspectic transfere of the 
sheath tank lines.