Bio-Rad Trans-Blot® Plus Cell - Manual (Page 13)

Section 3
Transfer Conditions
3.1 General Guidelines and Running Conditions
The electric field strength (V/cm) is the driving force in electrophoretic transfer.
Therefore, the most efficient transfers are obtained when the distance between the
electrodes of a blotting cell is reduced. The Trans-Blot Plus cell offers three
different electrode placements resulting in anode to cathode distances of 4, 7, and
10 cm for transfer of one, two, or three gel holder cassettes, respectively. In any of
these configurations, transfers may be performed under either high intensity or
standard field conditions.
High intensity field transfers require less than 5 hours to complete. Standard field
transfers require up to 16 hours to complete and are generally run overnight. In order
to produce such rapid transfers, high intensity transfers require higher power input
and consequently, produce more heat. Use of the Super cooling coil is required for
high intensity transfers and is recommended for standard field conditions, where the
run time is prolonged and usually unsupervised.
The following are recommended running conditions for a variety of transfer
buffers and electrode distances. Transfers may be performed under either constant
voltage or constant current settings. Constant voltage settings provide constant field
strength and tend to provide the most efficient transfer. Use of the Super cooling coil
should prevent heating when transferring under constant voltage. Please note that
the run times will need to be increased for gradient gels and may need to be
decreased if your proteins have a low molecular weight and transfer quickly.
Transfer conditions should be optimized for every individual application.
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