Bio-Rad Rotofor® and Mini Rotofor Cells - Manual (Page 3)

Section 1
Introduction
This kit was designed to familiarize you with your new Rotofor cell. The steps
outlined on the following pages will guide you through assembly of the Rotofor
cell and allow you to complete a fractionation run before running your own
sample.
The unique Rotofor system fractionates complex protein samples in free
solution using preparative isoelectric focusing. The Rotofor system is used for
the initial clean up of crude samples and in purification schemes for the elimi-
nation of specific contaminants from proteins of interest that might be difficult
to remove by other means.
The Rotofor cell provides up to 500-fold purification for a particular molecule
in less than 4 hours. Because isoelectric focusing is carried out in free solution,
fractions from an initial run can be collected, pooled, and refractionated, re-
sulting in 1,000-fold enrichment for a particular molecule. Purification using iso-
electric focusing is especially advantageous when protein activity must be
maintained. Bioactivity is maintained because the proteins remain in solution in
their native conformation.
The main component of the Rotofor cell is the cylindrical focusing cham-
ber with an internal ceramic cooling finger. The membrane core, with nineteen
parallel, monofilament polyester membranes divides the focusing chambers
into 20 compartments, each holding one fraction. Rotation of the chamber at 1
rpm stabilizes against convective and gravitational disturbances. After focusing,
the solution in each compartment is rapidly collected without mixing using the
harvesting apparatus supplied with the unit.
The use of interchangeable focusing chambers allows the Rotofor system to
accommodate a range of sample volumes. The Mini Rotofor chamber is used for
sample volumes of 18 milliliters containing micrograms to milligrams of total
protein. The Standard Rotofor chamber is used for samples of 35 to 60 milliliters
containing milligrams to grams of total protein.
*Patent No. 4,588,492
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