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PA-101 User Manual: Rev.1-1/05
The Cyto Pulse cell fusion coaxial electrode has been optimized to convert the PA-101
sine wave voltage to an efficient non-uniform alternating field for cell alignment. It also converts
the PA-4000 high voltage pulse(s) to a DC pulse electric field for cell fusion. The alignment
process using dielectrophoresis is a function of:
•
The time that the AC wave is on
•
The intensity of the AC electric field
•
The frequency of the AC electric field
•
The non-uniformity of the AC electric field
The first three parameters are selected using the PA-4000 interface software, and the last
parameter is a property of the coaxial electrode
The following chart shows the approximate intensity of the AC field for the three Cyto
Pulse electrodes at a set ac voltage of 75 volts-peak. The field is non-uniform the values below
are given at the inner electrode, mid way, and at the outer electrode.
Part No.
FE-25/400
FE-25/800
FE-20/1000
Gap
mm
2.5
2.5
2.0
Inner
V/cm
179
179
415
Mid
V/cm
135
135
373
Outer
V/cm
109
109
340
2.3.2
Step 2 – Fusion Pulse
The second step in electrofusion is to apply one or more high voltage pulses to the cells,
inducing membrane fusion. The voltage required must be above a threshold to induce
membrane breakdown and below a maximum voltage causing cell death. Threshold voltage is
approximately 0.5-1.5 volts across the cell membrane (1). The voltage across a cell is
approximately equal to:
Vt = 1.5 ∗ r ∗ E cos θ volts
where:
r = cell radius in cm
E = electric field intensity in v/cm
Θ = angle of the membrane in relation to the direction of the field
Electric fields 2-3 times threshold can be used. This should be optimized for the cells
used. Multiple fusion pulses may be more efficient than a single pulse. The table below gives
the approximate electric field intensity for a pulse of 800 volt in the Cyto Pulse electrodes.
Part No.
FE-25/400
FE-25/800
FE-20/1000
2-6
Gap
mm
2.5
2.5
2.0
Inner
V/cm
4087
4087
4430
Mid
V/cm
3107
3107
3990
Outer
V/cm
2496
2496
3624
Cyto Pulse Sciences, Inc., P. O. Box 609, Columbia, MD 21045 USA 410-787-1890