Bio-Rad Aurum Ion Exchange Mini Kits - Manual (Page 12)

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Section 6
Protocol
Please read the section “Guidelines for Aurum Ion Exchange Columns” before
proceeding.
1. Place an ion exchange column in a 12 x 75 mm test tube and allow the
resin to settle for at least 5 min.
2. Remove the cap and break off the tip from the bottom of the ion
exchange column. Return column to test tube.
3. Start gravity flow in the column and allow residual buffer to drain from the
column (approximately 2 min). If the column does not begin to flow, push
the cap back on the column and then remove it again to start the flow.
4. Once the residual buffer has drained, wash the column with 2 x 1 ml of
the appropriate Aurum AEX or CEX binding buffer using gravity flow.
Allow each wash to pass fully through the column and drain.
5. After the last wash, place the column in an empty 2.0 ml collection tube
and centrifuge for 10 sec at 1,000 x g in a microcentrifuge to dry resin
bed and frit. Do not overdry resin bed and frit. Discard the
collection tube.
6. Place the column in a clean 2.0 ml collection tube labeled “unbound”.
7. Load the sample in the appropriate buffer onto the column and allow the
sample to gravity filter through the column, collecting in the collection
tube. If the column does not begin to flow, push the cap back on the
column and remove it again to start the flow.
8. Place the column in another clean 2.0 ml collection tube.
9. Wash the columns with 0.3 ml of Aurum AEX or CEX binding buffer.
Unbound fractions can be combined for further analysis if desired.
Otherwise, unbound fractions can be discarded.
10. Place the column in a 2.0 ml collection tube and wash with 0.6 ml of the
appropriate Aurum AEX or CEX binding buffer. Centrifuge column for
20 sec at 1,000 x g in a microcentrifuge, collecting the eluate in the tube.
This wash can be discarded.
11. Place the column in a new 2.0 ml collection tube labeled “bound #1”.
12. Add 0.3 ml of the appropriate Aurum AEX or CEX elution buffer to the top
of the column and centrifuge for 10 sec at 1,000 x g.
13. Wash with an additional 0.3 ml of the Aurum AEX or CEX elution buffer
into the same “bound #1” tube. Centrifuge for 10 sec at 1,000 x g.
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