The packed columns were autoclaved on three
consecutive days prior to continuous flow operation. Media
was pumped in the upflow direction through the columns by
an 8 channel peristaltic pump (Ismatec, Switzerland). All
tubing (PTFE tubing, 1/16 in. o.d., Kimble Chase, Vineland, NJ;
PharMed Ismaprene 2-stop pump tubing, 1.52 mm i.d., Idex,
Germany) and column bed supports were sterilized either by
autoclaving or by contacting with a 10% bleach solution for
several hours followed by thoroughly rinsing with sterile
water.