Clean machines

Steven Merlin merlin at
Fri Feb 21 12:15:09 EST 1997

In regard to Claude's message of Tuesday, Feb 18th

>....Has anyone tried a protease/enzyme solution followed up by dilute hydrogen
>peroxide to sterilize?.....comments, plus or minus. ...

Most cell types we run on the FACScan or FACS Vantage are easily handled
with 0.5% Household bleach (1:10 dilution from the Chlorox bottle).
Immediately after the last sample, we make  a short 30 second flush with
water with high flow rate followed by bleach for 10 minutes. This is
followed by 10 minutes of sterile water, 2 minutes with automatic
dishwasher rinsing agent (Jet Dry in the USA, SUN Rinse Gloss by Lever in
Europe) and a final 3 minutes of sterile water. This method is also used
when cells are stained with AO, EB or PI.

When we are running cells known to be sticky due to producing mucins, e.g.,
Intestinal Epithelial cells, we do a fast flush with water followed by
Hyaluronidase enzyme for 10 minutes, then water, jet dry, etc as above. The
Hyaluronidase is purchased from Sigma (Cat# H2126) and 8 ug are dissolved
in 25 ml dH20. I always sonnicate my nozzle tips in the enzyme after IEL
cells are sorted as a preventive measure.

As for sterilizing the sorter, we routinely use 70% ETOH unless we were
doing work with bacteria previously, in which case 0.5% bleach or 3-6%
hydrogen peroxide or 20% Acetic Acid can be used. I have not observed any
corrosive effects on metal parts or connectors in either instrument in 4
years of operation. Most metal parts are stainless steel or anodized
protecting them from harsh chemicals.

Steven Merlin
University of Bern
FACS Core Facility
Murtenstraase 31
CH-3010 Bern, Switzerland
Lab:     ++41-31-632-8876
Office: ++41-31-632-9960
FAX:     ++41-31-381-8764
e-mail: merlin at

More information about the Cytometry mailing list