Bio-Rad Bio-Rex® 70 Cation Exchange Resins - Manual (Page 8)

Section 6
Resin Regeneration
Bio-Rex 70 resin is most efficiently regenerated in a
column. Regenerate to the sodium form by washing with
3 bed volumes of 0.5 N NaOH. The flow rate should not
exceed 1 ml/min per cm2 cross-sectional area of the
column. Conversion is complete when the pH becomes
greater than 9. Rinse with 4 bed volumes of deionized
water and equilibrate according to the procedure above.
Remember that the resin volume will approximately
double when converting from the hydrogen form to the
sodium form.
Section 7
Applications
Bio-Rex 70 resin has been used for the purification
and fractionation of enzymes, histones, endonucleases,
and toxins. Table 4 lists a variety of applications using
Bio-Rex 70 resin.
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the next portion is added. Never allow the liquid level
to drain below the top of the resin bed sample.
7. The actual flow rate that is used will depend upon the
application, the resin, and the column cross section.
To obtain flow rates for any given size column,
multiply the suggested flow rates in Table 3 by the
column cross-sectional area. Table 3 gives typical
flow rates of analytical grade resins.
8. If a cation-free solution is the goal, collect the
effluent. If the concentrated cations are of interest,
allow all of the sample to pass through the column,
then elute the sample with a solution containing a
counterion of higher selectivity than the bound cation.
Table 3. Suggested Flow Rates for Ion
Exchange Resin Columns
Flow Rates
Application ml/min/cm 2
Removing trace ions 5-10
Separations with very few components 1-3
Separations of multi-component samples 0.3-1.0
Using high resolution resins with small
particle size
0.1-0.2
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LIT206B 6/17/98 3:07 PM Page 10