Bio-Rad Bio-Beads S-X Media - Manual (Page 4)

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of the matrix is achieved with relatively nonpolar, aromatic
solvents. The beads are typically used with benzene,
toluene, xylene, carbon tetrachloride, and mixtures of sol-
vents.
Mechanism
Gel filtration, also called gel permeation, is the mode of
separation which occurs with Bio-Beads S-X beads. Large
compounds, greater than the molecular exclusion limit, pass
through the column unhindered, whereas small compounds,
within the molecular weight operating range, will be
retained in the column. The small compounds permeate the
pores of the Bio-Beads S-X beads, and thus they take longer
to pass through the column. This mechanism requires an
eluant which is mobile, and, therefore, Bio-Beads S-X beads
must always be used in a column mode.
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