Bio-Rad Media Sampler Pack - Manual (Page 4)

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Section 3
Preparation
UNOsphere ion exchange media are supplied fully hydrated in 100 mM NaCl in
20% ethanol as a 50% (v/v) slurry. For column packing, removal of the shipping
buffer is recommended.
Small volumes of UNOsphere media are easily washed in a Büchner funnel with
4–5 volumes of packing buffer. For large volumes, cycling through 3–4 settling and
decanting steps using the packing buffer in the shipping container is
recommended.
Complete removal of fines from UNOsphere media is not required due to the
narrow particle-size range. If fines have been generated during handling, resuspend
sediment and remove the milky supernatant before sedimentation is complete.
Repeat several times.
Section 4
Column Packing
Polymeric UNOsphere media may be packed using pressure, volumetric flow, or
vacuum packing methods. To pack highly efficient columns, it is recommended to
use a 20–50% slurry volume.
Packing Small Columns
This slurry packing method was designed to pack 25 ml of UNOsphere in a
conventional column with an internal diameter of 5–15 mm. All buffers should be
degassed. Since a relatively large volume of slurry is required, it is recommended
that a packing reservoir be used.
1. Prepare degassed 1.0 M NaCl, 20–50 mM buffer salt (see Table 2) referred to
herein as the packing buffer.
2. UNOsphere media are shipped as a 50% slurry. Measure 50 ml of suspended
slurry into a 100 ml graduated cylinder. Allow the resin bed to settle. Decant the
shipping solution away from the resin bed.
3. Add 50 ml of degassed packing buffer to resin.
4. Seal the cylinder and rotate it to suspend the resin. Caution: Do not mix with a
magnetic stir bar, as damage may occur. Larger amounts of slurry may be
mixed with a marine impeller at low to moderate speed.
5. Add 10 ml of packing buffer to the column. Pour in 75 ml of resin slurry.
6. Insert the column flow adaptor and flow-pack at a linear velocity of 1,200 cm/hr
with packing buffer for at least 10 min. Note the compressed bed height, stop
the flow, and adjust the flow adaptor to compress the bed 0.1–1.0 cm.
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