Bio-Rad ENrich™ High-Resolution Size Exclusion Columns - Manual (Page 10)

6 ENrich SEC Instruction Manual
Section 3 : Care of the ENrich SEC
Column
3.1 Regular Maintenance
To maintain performance, the column should be stored in 20%
ethanol, as described below, for storage periods longer than
2 days. Always run at least one CV of water between 20% ethanol
and running buffers.
If the column is exposed to air or if air bubbles are trapped in
the column.
1. Wash the column in the forward direction with 30 ml of water
at 0.25–0.5 ml/min.
2. Wash the column with 30 ml of 20% ethanol at
0.25–0.5 ml/min. Note that the backpressure will increase in
ethanol. Do not exceed 600 psi (4.1 MPa).
3. Wash the column with 30 ml of deionized water at the usual
operating flow rate as recommended in Table 1.
4. Re-equilibrate the column with the desired buffer.
If the column begins to show abnormally high backpressure.
If the backpressure increases abnormally, it is likely that the
column needs to be cleaned and/or the frit at the top of the bed
is clogged. First, clean the column using the method described in
section 3.3. If this is not sufficient, replace the top frit as described
in section 3.4.
3.2 Bed Height Adjustment
Under certain conditions of buffer composition, high flow rates,
or long-term use, the resin bed may compress, creating a void
between the frit and the top of the bed. Normally, the void can
be eliminated by turning the adjusting nut clockwise until the frit
just touches the top of the bed. If the bed compresses at high
flow rates, stop the pump and loosen the top fitting, then use
the adjusting nut to remove the void, retighten the top fitting, and
resume pumping buffer. If the bed has compressed from long-term
use, replace the top frit as a precaution.