Amersham Pharmacia Biotech EPS 3501 XL User manual

Electrophoresis Power Supply
EPS 3501 XL
User Manual
Manuel d’Utilization
Bedienungsanleitung
Manual del usuario
Manuale dell’operatore
18-1130-22
Edition AB
18-1130-22 AA EPS 3500XL omslag 99-02-10 13.17 Sidan 1

Program
HV on
Electrophoresis Power Supply - EPS 3501 XL
STOP
run exit
more
pause
continue
WARNING
High Voltage
set
enter
insert
delete
Voltage 100-120/220-240 VAC
Frequency 50/60 Hz
Power 260 W 4AMax
100-120 220-240
MAINS
Disconnect before servicing
I
0
Fig. 1. The front panel of the EPS 3501 XL.
Figure 1. Le panneau avant de l’EPS 3501 XL.
Abb. 1. Die Fronttafel des EPS 3501 XL.
Figura 1. Panel frontal de la EPS 3501 XL.
Figura 1. Pannello anteriore dell’EPS 3501 XL.
Fig. 2. The rear panel of the EPS 3501 XL.
Figure 2. Le panneau arrière de l’EPS 3501 XL.
Abb. 2. Die Rückwand des EPS 3501 XL.
Figura 2. Panel posterior de la EPS 3501 XL.
Figura 2. Pannello posteriore dell’EPS 3501 XL.
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1. Introduction. . . . . . . . . . . . . . . . . . . . . . 2
2. Safety information . . . . . . . . . . . . . . . . . 2
2.1 Safety precautions . . . . . . . . . . . . . . 2
2.2 In-built safety features . . . . . . . . . . . 3
3. Unpacking and installation. . . . . . . . . . . 3
4. Technical description . . . . . . . . . . . . . . . 4
4.1 Front panel . . . . . . . . . . . . . . . . . . . 4
4.1.1 Display . . . . . . . . . . . . . . . . . . 4
4.1.2 Keyboard . . . . . . . . . . . . . . . . 5
4.1.3 Output sockets . . . . . . . . . . . . 6
4.2 Rear panel . . . . . . . . . . . . . . . . . . . . 6
5. Operation. . . . . . . . . . . . . . . . . . . . . . . . 6
5.1 Overview. . . . . . . . . . . . . . . . . . . . . 6
5.2 Programming a method . . . . . . . . . . 6
5.3 Editing a program . . . . . . . . . . . . . 10
5.4 Running a program . . . . . . . . . . . . 11
5.5 Optional programming . . . . . . . . . 14
5.6 Choosing run parameters. . . . . . . . 15
5.7 Short instructions. . . . . . . . . . . . . . 17
6. Maintenance . . . . . . . . . . . . . . . . . . . . 18
7. Trouble shooting . . . . . . . . . . . . . . . . . 18
8. Technical specifications . . . . . . . . . . . . 19
9. Ordering information. . . . . . . . . . . . . . 20
Contents
Please read this entire manual to
fully understand the safe use of
EPS 3501XL
WARNING!
The Warning sign
highlights an instruction
that must be strictly
followed in order to
avoid personal injury. Be sure not to
proceeed until the instructions are
clearly understood and all stated
conditions are met.
CAUTION!
The Caution sign is used
to call attention to
instructions or
conditions that must be
followed to avoid damage to the
product or other equipment. Be sure
not to proceed until the instructions
are clearly understood and all stated
conditions are met.
Important user information
Declaration of conformity
Safety Standards
This product complies with the
requirement of the Low Voltage
Directive (LVD) 73/23/EEC through
the harmonized standard EN 61010-
1, 1993+ A1, 1992.
EMC Standards
This product complies with the
requirement of the EMC Directive
89/336/EEC through the harmonized
standards EN 50081-1 (emission)
and EN 50082-1 (immunity).
The CE symbol, and corresponding
declaration of conformity, is valid
for the instrument when it is.
– used as a “stand alone” unit or
– connected to other CE marked
Amersham Pharmacia Biotech
instruments, or
– connected to other products
recommended or described in
this manual and
– is used in the same state as it was
delivered from Amersham
Pharmacia Biotech except for
alterations described in this
manual.
Terms and Conditions of Sale
All goods and services are sold
subject to the terms and conditions
of sale of the company within the
Amersham Pharmacia Biotech group
which supplies them. A copy of these
terms and conditions is available on
request.
Should you have any comments on
this product, we will be pleased to
receive them at:
Amersham Pharmacia Biotech Inc.
654 Minnesota Street
San Francisco, CA 94107 USA
Trademarks
Amersham is a trademark of
Nycomed Amersham plc.
Pharmacia and Drop Design are
trademarks of Pharmacia & Upjohn
Inc.
Immobiline is a trademark of
Amersham Pharmacia Biotech
Limited or its subsidiaries.
© Copyright 1998 Amersham
Pharmacia Biotech AB - All rights
reserved
Office Addresses
Amersham Pharmacia Biotech AB
SE-751 84 Uppsala
Sweden
Amersham Pharmacia Biotech UK
Limited
Amersham Place Little Chalfont
Buckinghamshire
England HP7 9NA
Amersham Pharmacia Biotech Inc.
800 Centennial Avenue
P.O. Box 1327
Piscataway N.J. 08855-1327
USA
!
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1. Introduction
The Amersham Pharmacia Biotech Electrophoresis Power Supply EPS 3501 XL is a high quality, high
precision and safe power supply for electrophoresis applications that require advanced programming and
high voltage.
EPS 3501 XL is primarily designed for techniques using programming in several phases and/or voltage
gradients:
• 2-D (Two dimensional) electrophoresis using Immobiline™
• IEF (Isoelectric focusing) using Immobiline
EPS 3501 XL is also suitable for:
• DNA sequencing
• SDS-PAGE (Polyacrylamide Gel Electrophoresis)
• Native PAGE
• Agarose electrophoresis
• Electroblotting
• DNA pulsed field electrophoresis
Nine programs each with up to nine phases can be saved. Limiting values for voltage, current and power
as well as voltage gradients can be programmed for precise control of the electrophoresis. The
EPS 3501 XL automatically switches over the controlling parameter according to programmed limits and
gradients and conductivity variations in the system.
Two electrophoresis units can be connected to the EPS 3501 XL and run with the same programmed
method at one time.
2. Safety information
Extreme caution should be exercised in the operation of this instrument as it can develop sufficient
voltage and current to produce a lethal shock.
2.1 Safety precautions
To avoid any risk of injury, the instrument should only be operated by properly trained personnel and
always in accordance with the instructions provided.
Read this entire manual before using this power supply.
1. This instrument is designed for indoor use only.
2. The instrument must always be used with the protective earth lead of the power cord correctly
grounded to earth at the mains outlet.
3. To permit sufficient cooling, ensure that the vents in the rear and sides of the instrument are not
covered.
4. Do not operate the instrument in extreme humidity (above 95%). Avoid condensation by letting the
unit equilibrate to ambient temperature when taking the power supply from a colder to a warmer
environment.
5. Keep the instrument dry and clean. Wipe regularly with a soft damp cloth. Let the power supply dry
completely before use. If wetted, unplug the power supply until the instrument is dry.
6. Use only undamaged electrical wire and equipment approved for the voltages you will use. High
voltage wires must meet the requirements of the IEC 1010-2-031:1993 electrical standard.
Any electrophoresis equipment connected to the power supply should meet the requirements of the
IEC 1010-1:1993.
7. Note that the output is connected to the chassis/reference earth.
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2.2 Built-in safety features
The EPS 3501 XL has been tested and complies with the IEC 1010 (EN 60 1010-1) electrical safety
standard. The power supply also has several built-in safety functions:
1. Functional earth leakage.
Should the power supply be connected to an electrophoresis unit that has a leakage path to earth, the
EPS 3501 XL will detect this fault and the high voltage is turned off.
2. Start current check.
To ensure that an electrophoresis unit is connected correctly, the power supply checks that the resistance
is not higher than a specified limit at a low safety voltage (<40V). If this resistance is too high, the
voltage is turned off. Too high a resistance can also be caused by using buffers with extremely low
conductivity. The high voltage is also turned off in this case. This function can be disabled to perform
certain applications (see 5.5 Optional programming).
3. Sudden load change detection.
This function prevents accidents under running conditions due to a break in the electrical circuit such as
a bad connection to the electrophoresis unit. The high voltage is turned off in such an event.
Error messages are also shown on the display or sudden fails.
3. Unpacking and installation
Unpacking
Check the contents against the packing list supplied. Inspect for any damage that may have occurred
during transit. Report any damage immediately to your local Amersham Pharmacia Biotech
representative and to the transport company concerned.
Mains connection
Select the appropriate voltage range, 100-120 or 220-240 V, see Fig. 2 inside front cover.
Warning! If the power supply is connected to 220-240 V with the range set to 100-120 V, the
instrument can be severely damaged.
Select the appropriate mains cable and connect one end to the mains socket on the EPS 3501 XL power
supply, see Fig. 2 inside front cover, and the other end to an AC grounded outlet.
Switch on the power. Each time the instrument is turned on a self diagnostic test is done. If an error is
detected during the test a message will appear on the display and an alarm will sound.
Connection of the electrophoresis unit(s)
Connect the leads from the electrophoresis unit (red to red, and black or blue to blue), see Fig. 1 inside
front cover. The red lead is the positive and black or blue is the negative.
Warning! Use only undamaged electrical wire and equipment approved for the voltage you will use.
Two electrophoresis units can be run simultaneously with the same program. Please remember to double
the limiting current and power if two electrophoresis units are run at the same time. The voltage will be
the same regardless of the number of units.
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Local regulation for Great Britain
WARNING IMPORTANT
This appliance must be earthed.
The wires in the mains lead are coloured in accordance with the following code:
Green and yellow Earth
Blue Neutral
Brown Live
If the plug provided is unsuitable for your socket outlets, the plug must be cut off and suitable
plug fitted. The cut-off plug should be disposed of and must not be inserted into any 13 amp
socket as this can result in electric shock. The plug or adapter of the distribution panel should be
provided with 13 amps fuse. As the colours of the wires in the mains lead of this appliance may
not correspond with coloured markings identifying the terminals in your plug, proceed as follows:
The green and yellow wire must be connected to the terminal in the plug which is marked with the
letter E or by the earth symbol , or coloured green, or green and yellow. The blue wire must be
connected to the terminal which is marked with the letter N or coloured black. The brown wire
must be connected to the terminal which is marked with the letter L or coloured red.
NOTE
After replacing or changing a fuse, the fuse cover in the plug must be replaced with a fuse cover
which corresponds to the colour of the insert in the base of the plug or the word that is embossed
on the base of the plug, and the appliance must not be used without a fuse cover.
Only 13 Amps fuse approved to B.S 1362 A.S.T.A. should be used.
4. Technical description
4.1 Front panel
The front panel consists of an alphanumeric display, a keyboard with 9 membrane keys, a light emitting
diode (LED) that lights when voltage is applied (HV on) and connectors for two electrophoresis units.
4.1.1 Display
A 32 digit alphanumeric display guides you through the programming, shows current parameter values
during the electrophoresis and final parameter values afterwards. It also asks questions and shows error
messages. The display has an upper and lower row.
Fig. 1, see inside front cover, shows the display in the start position when power is switched on. The
mode (in this case SET) is shown in the upper row on the left. The program number, the chosen way of
controlling (step or gradient) and the phase number are shown in the center of the upper row. The
program number shown is that of the previously entered program. The blinking figure, in this case “1”,
indicates that it can be changed by using the Ô/Õ keys. The default way of controlling the power supply
is by step programming ( ). The upper right shows the programmed breakpoint for the actual phase. In
this case it is 0:00h. The lower left, middle and right positions show voltage, current and power
respectively, which all are zero for an unused program.
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4.1.2 Keyboard
SET ENTER
Enters a value or choice, confirms this if valid, and moves programming to the next field. Valid values
are voltage 35-3 500 V, current 1-400 mA, power 1-200 W, time 0:01-500 h, volthours 1-500 000 Vh,
milliampere-hours 1-25 000 mAh. In the RUN mode, pressing SET ENTER shows the programmed
parameters for the actual run. In addition, SET ENTER allows you to make changes in the program
during a run after first pressing PAUSE CONTINUE.
After a run, when in END mode, pressing SET ENTER puts the instrument into SET, its programming
mode.
CHANGE UP/CHANGE DOWN
Changes the parameter, value or other choice in the field which is blinking. Numerical values are
changed in an accelerating manner when a key is held down. Clicking a key changes the value in preset
increments. Parameters or units (e.g. Vh) and choices (e.g. yes/no) are changed with one key push. The
keys can also be used to switch between time and volthours in RUN, PAUSE and END. The values scroll
i.e. they automatically change from maximum to minimum value or vice versa.
RUN
PressingRUN starts the run and puts the program into RUN mode. The current values for voltage,
current and power are shown on the display. The elapsed time, volthours or milliamperehours are also
displayed. Switch between these last three parameters with Ô/Õ.
PAUSE CONTINUE
Puts the instrument in PAUSE mode and switches off the voltage. The display shows the status of the run
at the time the key was pressed. PAUSE CONTINUE only operates in RUN mode. Time, integrated
voltage and integrated current are retained. In the pause mode, SET ENTER can be used to make
changes in the program. Return to RUN mode by pressing PAUSE CONTINUE or by pressing RUN.
STOP
Stops the run and puts the instrument in END mode. The voltage is switched off and the end parameters
are displayed. Switch between time, integrated voltage and integrated current by pressing Ô/Õ. A run
cannot be continued after pressing STOP. Press RUN to run the same method again or press SET
ENTER to choose another program, program a new method or make changes in an existing method.
INSERT DELETE
Press INSERT DELETE to insert or delete a phase in a program. This function is activated in SET mode.
Note that a program must be completed by answering YES to the question “Last Phase?” in SET mode
or by pressing EXIT before you can use INSERT DELETE.
MORE
Places program in MORE mode. Gives access to some special functions. These include:
COPY: Copying a program.
CLEAR: Clearing a program
SETUP: Disabling the start current check.
MORE mode cannot be activated in RUN or PAUSE mode. Leave MORE by pressing EXIT.
EXIT
Stops the execution of an operation, such as the entry of a value. Only values/units that have already
been confirmed by SET ENTER are retained when EXIT is pressed. Note that if a phase contains zeros
when pressing EXIT, that phase will be deleted.
Returns the instrument to the mode that was left or to the start position in SET.
Ô/Õ
pause
continue
run
STOP
more
exit
Insert
delete
enter
set
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4.1.3 Output sockets
There are two sets of output sockets to allow two electrophoresis units to be connected and run at the
same time, see Fig. 1 inside front cover. The voltage output is 0–3500 V. The negative output socket
gives between 0 and –1750 V and the positive gives between 0 and +1750 V.
4.2 Rear panel
The rear panel is shown in Fig. 2, see inside front cover. On the rear panel there is:
1. A mains switch. Press in Ito switch on the power to the power supply. Press Oto switch off the
power.
2. A socket for the mains cable.
3. A switch for voltage range. The left position corresponds to 100–120 V and the right to 220–240 V.
4. Fan vents.
5. Operation
5.1 Overview
The operation of the EPS 3501 XL is described in the following sequence.
1. Programming or editing a method.
2. Editing a method.
3. Running a method.
Programming and running are discussed in more detail in the following two sections.
Blinking characters are shown as bold characters.
5.2 Programming a method
Figure 3 summarizes this operation.
Start position
When the power supply is switched on, the display shows the start position in SET mode. The previous
program set is shown and that program number is blinking.
If the power supply is switched on for the first time or if the program has been cleared, see section 5.5,
the default way of controlling is step ( ), the breakpoint parameter is time (h), the alarm is off and the
values are all zero.
SET: 11 0:00h
0V 0mA 0W
Choosing a program
Up to nine programs, each with up to nine phases, can be entered. Press SET ENTER to confirm the
program shown by the number on the display or use Ô/Õkeys to choose another. Confirm with SET
ENTER.
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SET: 2 1 0:00 h
1000 V 10 mA 0W
SET: 2 1 0:00 h
0V 0 mA 0 W
SET: 2 10:00 h
0 V 0 mA 0 W
SET: 2 1 0:00 h
1000 V 10 mA 0 W
SET: 2 1
STEP/gradient
SET: 11 1 Vh
500 V 1 mA 5 W
enter
set
Select by
Confirm by
SET: 2 1 0:00 h
1000 V 10 mA 10 W
SET: 2 1 0Vh
1000 V 10 mA 10 W
1. Choose Program Number
(1→2)
2. Choose Step or Gradient
mode. (Step)
3. Confirm Phase number (1)
4. Set Voltage limit (step) or
Voltage endpoint
(gradient).
(0→1000 V)
5. Set Current limit.
(0→10 mA)
6. Set Power limit
(0→10 W)
7. Choose Breakpoint unit
(h, Vh or mAh) or no
breakpoint (OFF).
(h→Vh)
(h→OFF)
8. Set Breakpoint
(0→1000 Vh)
9. Last Phase,
YES or NO?
10. Choose Alarm OFF or ON.
(ON)
11. The program is ready.
enter
set
1st Phase Other phases
SET: 2 1 1000 Vh
Last phase ? Y
Alarm Phase 1? N
Phase: - - - -
SET: 21A1000 Vh
1000 V 10 mA 10 W SET: 21 OFF
1000 V 10 mA 10 W
YES
Vh
NO
Confirm by
enter
set
Select by Confirm by
enter
set
Select by Confirm by
enter
set
Select by Confirm by
enter
set
Select by Confirm by
enter
set
Select by Confirm by
enter
set
Select by Confirm by
enter
set
Select by Confirm by
enter
set
Select by Confirm by
Breakpoint OFF
Fig. 3. Step-by-step summary of programming.
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Choosing step or gradient programming
Press SET ENTER to confirm step ( ) or use Ô/Õ keys to choose gradient ( ). Confirm with SET
ENTER.
Note that your choice of gradient or step programming applies for all phases within the program and
you will only be asked to choose one of them when programming the first phase.
Choosing step means that voltage, current and power limiting values are programmed. The
electrophoresis will be controlled by one of these limiting values, which means that it is run at either
constant voltage, current or power. The EPS 3501 XL automatically switches over the controlling
parameter according to programmed limits and conductivity variations in the system. Thus the
controlling parameter can switch within a phase.
Table 1 and Fig. 4 illustrate a step program. The programming and running of this application are
shown as Figs. 3 and 7.
Table 1. The parameters of a step program.
Phase Voltage Current Power Volthours
number (V) (mA) (W) (Vh)
1 1 000 10 10 1 000
2 500 10 5 120
3 2 000 20 15 1 000
4 3 500 30 25 1 500
Choosing gradient ( ), means that a voltage endpoint for the actual phase is programmed together with
current and power limiting values. A linear voltage gradient is made with zero (for the first phase) or the
programmed endpoint of the phase before (for the next phases) as starting point and the programmed
endpoint as endpoint. The electrophoresis will be controlled by this voltage gradient provided the
limiting current or power is not attained. The EPS 3501 XL thus automatically switches over the
controlling parameter according to the programmed limits and conductivity variations in the system.
Fig. 4. Programming the voltage limiting profile in STEP mode. The parameters shown are the same as those
listed in Table 1.
3 500
2 000
1 000
500
Voltage (V)
Phase 1
1 000 Vh
120 Vh
Phase
2
Phase 3
Phase 4
1 000 Vh
1 500 Vh
1 2
Time (h)
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To illustrate voltage gradient programming, the programming for the IEF part of a 2-D electrophoresis
with Immobiline DryStrip™ is shown in Table 2 and Fig. 5. Note that the first phase is a very steep
gradient to reach the 500 V start level (0 - 500 V, within 1 Vh). The next phase is actually a step since
the endpoint for phase 2 is 500 V which is the same as the endpoint for phase 1. Phase 3 is the “real”
gradient, the voltage is changed from 500 to 3 500 V in 5 hours. The last phase is a step again, the
endpoint voltage is the same as for the phase before and the voltage will remain on 3 500 V for 9.5
hours.
Table 2. The parameters of a gradient program.
Phase Voltage Current Power Time Volthours
number (V) (mA) (W) (h) (Vh)
1 500 1 5 0:01 * 1 *
2 500 1 5 5 2 500
3 3 500 1 5 5 10 000
4 3 500 1 5 9.5 33 250
* The ramping from 0 to 500 V should be done as quickly as possible. The smallest possible time that can be set is 1 minute and the smallest
possible Vh that can be set is 1 Vh. Vh was chosen for this program as breakpoint unit.
Choose phase number
Choose phase number with Ô/Õand confirm with SET ENTER. For a new program the default phase
number is 1. If the first phase has been programmed and the question “Last phase ?” is answered by NO,
the default number is 2 and so on.
Setting voltage, current and power
The display will now flash for the set voltage limit (step mode) or voltage endpoint (gradient mode).
Using the Ô/Õ keys, select the voltage limit or voltage endpoint desired for the run. Confirm with SET
ENTER.
Fig 5. Programming the voltage limiting profile in GRADIENT mode. The parameters shown are the same as
those listed in Table 2.
3 500
Voltage (V)
500
Phase 1
1 Vh
Phase 2
2 500 Vh
Phase 3
10 000 Vh
Phase 4
33 250 Vh
5 10 19.5
Time (h)
12
34
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Repeat the same procedure for limiting current and limiting power.
Programmable values for voltage are 35-3 500; current, 1–400 mA; power, 1–200 W.
Setting breakpoint
Choose between automatic or manual break. For automatic break, choose breakpoint unit in either
hours (h), volthours (Vh) or milliamperehours (mAh). Select the correct unit or, for manual break,
choose “OFF” with Ô/Õ. Confirm with SET ENTER.
Note that the breakpoint unit is valid for all phases within the program and you will only get this
question when programming the first phase, see “Other phases” bypass in Fig. 3.
If h, Vh or mAh is chosen, the display will flash for the break value for the actual phase. Set the value
with Ô/Õand confirm with SET ENTER. Programmable values for time are 0:01–500 h, volthours,
1–500 000 Vh, milliamperehours, 1-25 000 mAh.
If OFF is chosen, you have to break the electrophoresis manually by pressing STOP and only one phase
can be entered. The program will go back to the start position and the program number will flash.
Last Phase?
After programming the breakpoint you are asked if this is the last phase or not. Select YES or NO with
Ô/Õ and confirm with SET ENTER.
If YES is selected, no more phases will be added and the alarm question will be shown, see below.
If NO is selected, the next phase number for the program will be shown on the display together with
zero values for all parameters. Program the next phase according to “Setting voltage, current and power”
above and Fig. 3 point 4. Up to nine phases can be programmed.
Choosing alarm
The alarm can be set separately for each phase. The following question is shown:
Alarm Phase 1? Select YES or NO with Ô/Õ and confirm with Ô.
If YES is selected in a 4 phase program this will be indicated by changing from - - - - to 1 - - - after
“Phase:” on the lower row in the display. Then you will be asked about an alarm for the next phase.
After answering YES or NO for the last phase, the start position in the SET mode will be shown. If
alarm is selected for a phase a small “A” appears on the right of the phase number, i.e. 2 2A.
Back to start position
The program is now back to the start position in the SET mode with the program number flashing. It is
possible to go back to this position at any stage during programming in SET mode by pressing EXIT or
STOP. Note that the program is automatically saved with all choices that have been confirmed by SET
ENTER when EXIT or STOP is pressed. If a phase containing invalid values (zeros) is left, this phase will
be deleted.
Disabling the start current check
See Section 5.5 if you want to use this feature.
5.3 Editing a program
Changing a parameter value
To change a parameter value, move to the start position in SET mode by pressing EXIT or SET ENTER
and choose program number as described on p. 11. If the programming mode (step or gradient) is
changed it will be changed for all the phases within the program.
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Select phase number by Ô/Õ and move in the program with SET ENTER to the value to be changed.
Change with Ô/Õ and confirm with SET ENTER. Press EXIT.
Inserting and deleting a phase
Inserting and deleting a phase is described schematically in Fig. 6.
Note that you must first enter a phase before it can be inserted or deleted:
1. If needed, change program number by entering the start position in SET mode with SET ENTER or
EXIT, changing the number with Ô/Õ and confirming by SET ENTER.
2. Bypass the mode question with SET ENTER.
3. Change to the desired phase number by Ô/Õ and confirm with SET ENTER.
Choose to delete the phase shown on the display or insert a new phase with this phase number by
pressingÔ/Õ and confirm with SET ENTER.
If DELETE is chosen, the selected phase will be deleted and the program will move back to the position
with the phase number blinking. Note that by deleting a phase, the numbers of the following phases will
decrease by 1.
If INSERT is chosen, the program will enter the same position and the new phase can be programmed as
a new phase (see section 5.2 and Fig. 3, points 4–8). After entering the breakpoint, the question “Last
Phase?” will be bypassed and the starting point for the next phase will be entered. Note that by inserting
a new phase the number for the old phase with that number and the numbers for the following phases
will increase by 1.
Adding a phase after the last phase is done by entering the last phase as above, moving to the question
“Last Phase?” and answering NO. The program will jump to the start position for programming a phase
with the phase number blinking. Proceed with programming as described for a new program.
It is not possible to insert or delete a phase for a running program.
Editing a running program
See section 5.4
Copying and clearing a program
See section 5.5.
5.4 Running a program
Connect the leads from the electrophoresis unit (red to red, and black or blue to blue). Red is positive
and black or blue negative. Up to two electrophoresis units can run at the same voltage at one time.
Please remember to double the maximum current and power conditions if two units are to be run.
Voltage will be the same regardless of the number of units. The current should also be doubled if two
gels are run on the same unit.
Running a program is described schematically in Fig. 7.
Choosing a program
Press SET ENTER and select the program you wish to run by pressing Ô/Õ until the value is correct.
(Omit this step if you have just programmed or edited a method as described in sections 5.2 and 5.3.)
Running
Press RUN to start the electrophoresis. Information about the status of the start current check will be
displayed for a few seconds. The display will then show current values for voltage, current and power
and one of elapsed time, volthours or milliamperehours. You can switch between showing the
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elapsed time, volthours or milliamperehours by Ô/Õ. The parameter controlling the electrophoresis is
underlined.
A light emitting diode shows when voltage is applied (HV on).
If no current is displayed or if “HALT: Low start current” is shown, please check the electrical
connections to the electrophoresis equipment.
Pausing
You can interrupt the electrophoresis for sample loading and/or changing the program by pressing
PAUSE CONTINUE. Voltage will no longer be supplied, the “HV on” LED goes off, and you may safely
load your samples. The display shows the status of the run when PAUSE CONTINUE was pressed.
Switch between time, integrated voltage and integrated current for the phase running when PAUSE
CONTINUE was pressed with Ô/Õ.
When sample loading is complete, press either PAUSE CONTINUE again or RUN to continue the run
from where it was interrupted.
Editing a running program when in PAUSE
When in the PAUSE mode you can also press SET ENTER to make changes in the program. This mode is
called the P-SET mode. When the P-SET mode is entered you can make changes as described in the
SET: 2 21000 Vh
2000 V 20 mA 15 W
SET: 2 2 00:00 h
0V 0 mA 0 W
Fig. 6. Inserting and deleting a phase in a program.
Insert Phase 2
INS/del
SET: 2 11000 Vh
1000 V 120 mA 10 W
SET: 2 1
step/GRADIENT
SET: 11A1 Vh
500 V 1 mA 5 W
1. Choose Program Number (1→2)
2. Confirm Step or Gradient.
(Step)
3. Choose Phase number (2) and
enter INSERT/DELETE
4. Choose INSERT or DELETE
Programming point 4
5. Program
a new
phase 2.
INSERT DELETE
5. Back to new
Phase 2 start
position.
Old Phase 2
deleted.
enter
set
Select by Confirm by
enter
set
Confirm by
Insert
delete
Select by Enter by
enter
set
Select by Confirm by
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editing section (5.3, Changing a parameter value). It is not possible to insert or delete a phase for a
running program. The P-SET mode is the same as the SET mode apart from restrictions in setting the
breakpoint. Naturally, it is not possible to enter a time, integrated voltage or current that is already
passed.
Press EXIT or PAUSE CONTINUE to go back from P-SET to PAUSE. Press RUN or PAUSE
CONTINUE to proceed with the electrophoresis.
View programmed values
It is also possible to view the programmed values during a run by pressing SET ENTER. Note that no
values can be changed here. Only one phase is shown at one time. Switch to another phase by using
Ô/Õ. The display returns automatically to show RUN values after 5s. Alternatively use EXIT or RUN.
Stopping the run and viewing end parameter values
When the programmed time, volthours or milliamperehours for the last phase is attained, the program
will enter the End mode. It is also possible to break the run manually by pressing STOP.
In both cases, the voltage, current and power will go to zero as indicated by the “HV on” LED switching
off. The end parameter values are displayed. Switch between total elapsed time, integrated voltage or
integrated current for all phases in the program by Ô/Õ.
SET: 2 1A1000 Vh
1000 V 10 mA 10 W RUN: 2 1A1000 Vh 900 V 10 mA 9 W
RUN: 2 1A5 Vh
500 V 10 mA 5 W
SET: 21A1000 Vh
1000 V 10 mA 10 W
SET: 11 1 Vh
500 V 1 mA 5 W
Select by
run
Start by
PAUSE: 2 1A1000 Vh
900 V 10 mA 9 W
P-SET: 2 1A1000 Vh
1000 V 10 mA 10 W
RUN: 2 4A880 Vh
2500 V 10 mA 25 W END: 2 4A3000 Vh 2500 V 10 mA 25 W
END: 2 4A3620 Vh
3125 V 8 mA 25 W
enter
set
exit or wait 5 s
pause
continue
pause
continue
run
or enter
set pause
continue
exit
or
Programming
STOP
1. Choose Program Number. (1→2)
2. Start the run.
3. During a run you can view the
settings. It is also possible to
interrupt the run and make
changes in the program.
4. Stop the run manually.
5. The run is stopped automatically.
Fig. 7. Running, viewing and pausing a program.
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An alarm will sound at the end of each phase if selected in the program. You can stop the alarm after the
last phase by pressing STOP. A run cannot be continued after pressing STOP. Disconnect the leads and
proceed with post-electrophoretic techniques. Since diffusion will begin as soon as the voltage is turned
off, you should remove the gel and begin staining, blotting or autoradiography immediately.
5.5 Optional programming
Some special functions are placed in MORE. These are:
COPY: Copying a program.
CLEAR: Clearing a program.
SETUP: Disabling the start current check.
The MORE mode is described in Fig. 8.
MORE: SETUP
copy/clear/SETUP
Fig. 8 . Optional programming in MORE mode.
CLEAR: Program 1
Used: P12--56789
SET: 11 1 Vh
500 V 1 mA 5 W
Select MORE by
Selected by
Confirm with
more
1. Enter MORE
2. Choose COPY or CLEAR a
program or choose SETUP for
disabling the start current check.
enter
set
COPY: P1→P?
Used: P12--56-89 SETUP: P1
Select program
3. Choose Program
(1→8) CLEAR
3. Choose Program to
copy from. (1→1)
COPY SETUP 3. Choose Program
(1→2)
Selected by
Confirm with enter
set
Current check at
start? YES/no
Selected by
Confirm and
Exit by enter
set
4. Choose start
current check
YES or NO
Selected by
Confirm with enter
set
Prog. P8 Cleared
4. Message
Selected by
Confirm with enter
set
COPY: P1→P3
Free: P--34--7--
4. Choose
Program
destination
(3→4)
Selected by
Confirm with enter
set
Prog. P1 copied
to P4
5. Message
Wait 2s
6. Back to SET
mode
Wait 2s
SET: 11 1 Vh
500 V 1 mA 5 W
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Copying a program
Enter the MORE mode by pressing MORE . Choose between COPY, CLEAR and SETUP with Ô/Õ and
confirm with SET ENTER.
After choosing COPY you are asked which program should be copied. Programs that can be copied are
shown in the lower row on the display. Select with Ô/Õ and confirm with SET ENTER.
Select to which program number the program should be copied. Empty (available) programs are shown
in the lower row. Select with Ô/Õ and confirm with SET ENTER.
If an already programmed method is chosen, a warning is shown: “Program 7 not empty: Copy?”. If
you answer YES, the program with this number is replaced by the one you have copied.
A message confirming that your instruction has been carried out is shown for a few seconds.
The program returns automatically to the start position in SET mode.
Deleting a program
Enter the MORE mode by pressing MORE Choose between COPY, CLEAR and SETUP with Ô/Õ and
confirm with SET ENTER.
After choosing CLEAR you are asked which program should be cleared. Programs that can be cleared
are shown in the lower row on the display. Select with Ô/Õ and confirm with SET ENTER.
A message confirming that your instruction has been carried out is shown
for a few seconds.
The program returns automatically to the start position in SET mode.
Disabling the start current check
You can disable the start current check that otherwise detects that the resistance is not higher than a
specified limit. Disabling this check is important when performing certain applications such as the first
step in 2-D electrophoresis using Immobiline DryStrip. This disabling function is set in the MORE mode
instead of the SET mode in order not to confuse users who do not need this feature, and for safety
reasons.
Enter the MORE mode by pressing MORE. Choose between COPY, CLEAR and SETUP with Ô/Õ and
confirm with SET ENTER.
After choosing SETUP, the program asks you for the program number and if you want to keep the start
current check.
Choose program number and change between “YES” and “NO” by Ô/Õ and confirm with SET
ENTER. Choosing “NO” for start current check means that the function is disabled and high voltage
can be applied despite a very high resistance. Leave the MORE mode by SET ENTER or EXIT.
Warning! By disabling the start current check, the power supply can deliver high voltage even if it is
not connected to electrophoresis equipment.
Note that a message showing whether the start current check is ON or OFF is shown for a few seconds
every time RUN is pressed.
5.6 Choosing run parameters
EPS 3501 XL is an automatic cross-over power supply that allows the user to set limits for voltage,
current and power. It is also possible to program linear voltage gradients. During electrophoresis, only
one of the parameters is limiting at a time. The limiting parameter determines, together with the
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conductivity in the electrophoresis system, the values for the other two parameters. Voltage, current,
power and conductivity are related by the following equations:
U = I / L (1)
P = U x I (2)
Where U = Voltage, I = Current, P = Power and L = Conductivity
Equation (1) is more familiar if the conductivity is replaced by the reciprocal resistance (R):
U = R x I (Ohm´s law)
The electric field E, measured in V/cm, is the driving force behind electrophoresis.
E = U / d
where E = Electrical field strength, U = Voltage, d = distance
The electrical field strength is achieved by applying a voltage. The higher the voltage, the faster the
electrophoresis. Fast electrophoresis is beneficial since it counteracts diffusion.
The disadvantage of increasing the voltage too much is that most of the generated electrical energy, the
product of power and time, is transformed to heat. Therefore cooling of electrophoresis equipment is
recommended. Cooling will also reduce “smiling” effects which are caused by mobility differentials
across an electrophoresis gel resulting from poor heat transfer. Since the cooling efficiency cannot be
increased indefinitely, the power should be limited when programming the power supply.
The parameter that should be chosen as the constant and thus control the electrophoresis depends on the
type of electrophoresis. In the case of homogeneous buffers throughout the system (same electrode and
gel buffer), the conductivity is constant during the electrophoresis. If the conductivity is constant, the
voltage will be proportional to the current and the power to the square of the current, according to (1)
and (2). This means that the result of the electrophoresis will be the same, regardless of which parameter
is chosen as the constant. For historical and practical reasons, voltage is most commonly used for
regulation. Submarine gel electrophoresis of DNA/RNA and pulsed field electrophoresis are usually run
at constant voltage. SDS-PAGE using continuous buffer systems is run at constant voltage or current.
For discontinuous buffer systems, the resistance will increase as the electrophoresis proceeds due to a
decrease in conductivity. Running at constant voltage will result in decreasing current and power.
Constant voltage will thus be “safe” in the respect that the power will not increase and produce more
and more heat. On the other hand, the separation will slow down and impair resolution due to an
increased time available for diffusion. Running at constant power would give a faster electrophoresis and
controlled power, while running at constant current would, at the first sight, seem to be problematic
because of increasing voltage and power.
During discontinuous electrophoresis, however, the voltage is not distributed evenly across the gel. These
gels have a region with low ionic strength that causes a high electrical field strength. This region
increases as the electrophoresis proceeds. This means that the main part of the voltage is spread over a
greater and greater distance and a higher and higher power is tolerated. This is the reason why constant
current is chosen for such applications. It is, however, recommended to also limit the power as a
precaution against overheating the gel. The power supply will probably switch over to limiting power at
the end of the run due to increased voltage.
The crossing-over between different parameters controlling the electrophoresis can be illustrated by IEF
(isoelectric focusing) using carrier ampholytes. A graphical representation of the changes in power,
voltage and current that may occur during a typical IEF run is given in Fig. 9. Since the pK values of the
carrier ampholytes and the proteins are temperature dependent, IEF must be carried out at a constant
temperature. Therefore cooling of electrophoresis equipment and controlling by power is recommended.
The main part of the IEF is thus controlled by power (phase II). The conductivity is gradually decreasing
because the carrier ampholytes and sample will loose their net charge during the build up of the pH
gradient. Thus the current will decrease and the voltage increase at constant power. During the early
stage of the formation of the pH gradient it is important to limit the current. Otherwise the gradient will
be irregularly shaped (phase I). The conductivity is not constant along the gel so it is important to also
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limit the voltage. This means running at constant voltage for the last phase (phase III) to prevent local
overheating.
For detailed information about parameter values, always follow the gel supplier´s recommendations.
5.7 Short instructions
This section summarizes the main programming points covered earlier in this chapter. Use it as a check
list once you are familiar with the detailed programming, editing and running instructions. Refer also to
the separate schematic operating guide included with the power supply. We recommend you keep this
schematic guide close by the instrument.
1. Turn mains power ON. The display should have the program number flashing.
2. Press SET ENTER for the actual program number, or use Ô/Õ to select the program number desired.
Press SET ENTER.
3. The display now asks if you wish to perform a step or gradient program. Select with SET ENTER,
or with Ô/Õ followed by SET ENTER.
4. The display will blink for phase 1. Press SET ENTER to confirm.
5. For each of the parameters Voltage, Current and Power, press Ô/Õ until the value desired is reached.
If gradient mode has been selected, the voltage endpoint for the phase should be chosen. Confirm by
pressing SET ENTER after each parameter, and the display will automatically move to the next
parameter.
6. Choose between manual break or automatic break. For automatic break, choose breakpoint unit in
either time (h), volthours (Vh) or milli-amperehours (mAh). Select the correct unit or, for manual
break, choose “OFF” with Ô/Õ. Confirm with SET ENTER.
7. If hours, volthours or milliamperehours were chosen, set the value to be used for the breakpoint with
Ô/Õ and SET ENTER.
8. If you only want one phase, press SET ENTER for YES to confirm that this is the last phase. If more
phases are required, select NO with ‘/’ and confirm with SET ENTER. To add more phases, repeat
steps 5–8, until the desired number of phases have been programmed. Up to 9 phases can be
programmed.
III III IV
Power
Voltage
Current
Preset time Alarm
Fig. 9. Changes in power, voltage and current during an IEF run.
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9. After all phases have been programmed, you will be asked if you wish for alarms to sound after the
different phases. Press SET ENTER for NO or change to YES and then press SET ENTER.
10.When programming is completed, connect your electrophoresis unit to the outputs, and press RUN.
6. Maintenance
Check regularly that the fan is working properly. Wipe the instrument regularly with a damp cloth. Let
the instrument dry completely before use. Otherwise no user maintenance is necessary. All servicing
should be entrusted to qualified personnel only. Please contact your local Amersham Pharmacia Biotech
representative for more service information.
7. Trouble shooting
If an error that can be corrected by the user occurs, either during a run or when switching on
the power supply, the program enters the HALT mode and the output is switched off. Four
different types of errors can cause HALT. The following list shows the error message on the
display, the cause and the remedy.
If a serious error occurs, the program enters the FAIL mode. The output is switched off and an
error message is shown in the display.
FAIL:Code No: xxx
Call service
Please read the error code number and contact your Amersham Pharmacia Biotech representative.
Error message
HALT: Low start
current!
HALT: Ground
leakage current
HALT: Mains
Voltage too low!
HALT: Mains fail
Program stopped
Cause
The current is less than the lower limit.
This can be due to incorrect
connection of the electrophoresis
equipment or due to use of buffers with
extremely low conductivity.
The current to ground leakage in the
electrophoresis unit is too high.
The mains voltage is too low, see
Specifications.
Mains power failure for more than 7 s.
Remedy
1. Check connections and/or buffers.
2. Press MORE, switch off the start
current check in the MORE mode.
IMPORTANT! Read Section 5.5 first.
Check the electrophoresis unit.
Check voltage selector.
Check mains voltage.
Press PAUSE CONTINUE to continue
running a program or STOP to interrupt
the run.
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