Bio-Rad Bio-Beads S-X Media - Manual (Page 10)

position. Then, displace the tetrahydrofuran with 3 bed volumes
of chloroform.
Flow Rate
Bio-Beads S-X beads have the capacity for different flow
rates, depending on the crosslinkage. The 1% and 2%
crosslinked resins (Bio-Beads S-X1 beads) are very soft when
fully swollen and should only be used in gravity flow proce-
dures. Bio-Beads S-X3 beads can withstand 5 ml/min with a
backpressure of 300 psi. Bio-Beads S-X8 and S-X12 beads can
withstand up to 5,000 psi backpressure.
Collecting Fractions
Separated compounds are often collected for further analy-
sis. Fractions can be constantly collected, for example in 2 ml
increments, or they can be collected specifically when the com-
pound of interest is eluting. In order to know when the com-
pounds are eluting from the column, pass the eluant through a
detector. Ultraviolet (UV) detectors are commonly used, though
a preparative cell may be necessary so that the flow is not
restricted too much. Use the information from the UV chro-
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