SAMPLE LOADING OPTIONS

The BioLogic DuoFlow system supports several methods for sample loading. Typically a sample is loaded through a static fixed volume loop on the AVR7-3 inject valve. When large volume sample injections are required, the following options are available:

• Sample loading through the Workstation pumps: The SV5-4 or SV3-2 valve may be used to load large volumes of sample through the Workstation pumps. Refer to page 2-31 and page 2-33 for the discussion of these valves.

• Sample loading through a DynaLoop sliding-piston loop: When used with an AVR7-3 inject valve, the DynaLoop may be used for large volume sample loading or repetitive injections of smaller volumes of sample. The DynaLoop comes in two sizes: 25 and 90 ml volume.

• Sample loading through an auxiliary pump, such as the EP-1 Econo pump (EP-1) or the Econo Gradient Pump (EGP). When used with an AVR7-3 inject valve, an EP-1 or EGP pump may be used for large volume sample injections. (Placing an AVR9-8 valve before the pump inlet allows loading of multiple samples. Refer to the discussion of the AVR9-8 valve for details.)

2.8.1 DynaLoop Large Volume Sample Injection Loop

The DynaLoop, available in 25 ml and 90 ml sizes, is a sliding-piston dynamic loop for injection of a large sample volume or repetitive injections of smaller samples. The DynaLoops have a sliding piston that

functions like a syringe. The loop is installed on the AVR7-3 in place of the static loop. (Refer to figure 2-24). Sample is loaded into the DynaLoop’s sample end connector through port #2 on the AVR7-3 valve and may be loaded with a syringe or auxiliary pumps, for example Bio-Rad’s Econo Gradient Pump or EP-1 pump. The loading of the sample pushes the DynaLoop’s sliding seal towards the buffer end connector. As solution flows into the buffer end of the DynaLoop it pushes the sample into the system.

Figure 2-23. DynaLoop 0 5 10 15 20 25 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 SAMPLE END PORT 6 ON AVR 7-3 SLIDING SEAL ASSEMBLY BUFFER END PORT 3 ON AVR 7-3

Figure 2-24. Plumbing the DynaLoop for use with an Inject Valve

When plumbed directly to the AVR7-3 inject valve, the DynaLoop functions just like a static sample loop. The sample end of the DynaLoop should be plumbed to port 3 and the buffer end to port 6 of the inject valve. The valve’s operation and sample loading are controlled automatically, simplifying the sample injection process and insuring precise sample loading and gradient formation. The DynaLoop can be filled using a syringe or auxiliary pump.

Use a 1/4x28 to female Luer adapter between the sample load syringe and the AVR7-3 valve port 2 makes filling the loop much easier.

Consult the DynaLoop user's manual for additional information. 6 7 1 2 3 4 5 COLUMN DYNALOOP WORKSTATION PUMP AVR7-3 LOOP OVERFILL TO WASTE WASTE SYRINGE OR AUXILIARY LOAD PUMP

2.8.2 Model EP-1 Econo Pump

The Model EP-1 Econo pump is a two-channel, bi-directional, variable speed peristaltic pump for low- pressure chromatography. The EP-1 offers a full range of features to facilitate ease of use as a stand-alone pump or as an accessory to the DuoFlow System to load large volumes, especially onto low pressure columns. This instrument is described in detail in its separate documentation. Features of the EP-1 include:

• The EP-1 has preset calibration for common tubing sizes and manual calibration for nonstandard size tubing.

• It controls various fraction collectors, including the BioFrac, Model 2110, and Model 2128 fraction collectors.

• It can control the run length with a programmable total run volume. • It is coldroom compatible.

Figure 2-25. Model EP-1 Econo Pump

The EP-1 Econo pump is ideal for loading samples onto a low-pressure column. When using a low-pressure column, such as an Econo-Pac cartridge, remove the 40 psi backpressure regulator from the post-column position. Place it at the outlet of the Workstation pump. This will allow the check valves to properly seat and ensure pump flow performance.

The EP-1 Econo pump must contain firmware version 2.12 or higher to function with the BioLogic DuoFlow system. To confirm the firmware version, simultaneously press and hold down the Direction key and the down arrow key on the front panel of the EP-1 Econo pump. If the Econo pump does not have the correct firmware version, contact BioRad for information on how to upgrade the pump.

The EP-1 Econo pump receives start/stop signals only. The flow rate of the EP-1 Econo pump is set from the pump, and the flow rate is recorded in the yellow data entry boxes of the Load/Inject Sample dialog box. The DuoFlow system starts/stops the Aux pump and cannot control the flow of the EP-1 Econo pump. The correct flow rate must be set at the EP-1 Econo pump.

ECONO PUMP ml min ml/min % 0.8 1.6 3.2 CAL Vo Vt

Figure 2-26. Connecting an EP-1 Econo Pump to the BioLogic DuoFlow Workstation To connect the EP-1 Econo pump with the DuoFlow system, make the following cable connections:

1. On System Cable 7 locate the red and blue wires at the wire end of the cable and connect them to the DuoFlow Workstation.

Cut short all other wires and insulate with tape.

a. Connect the red wire to pin 6 of the Aux connector. b. Connect the blue wire to pin 9 of the Aux connector.

2. Plug the 8-pin mini-DIN connector into the Aux connector on the rear panel of the Econo pump. PharMed tubing is recommended for use in the pumphead of the EP-1 Econo pump. For additional

information on this pump, consult its user manual. The illustration below shows the Aux pump connected to port 3 of the Inject Valve.

Figure 2-27. Example of Large Sample Loading using an Econo Pump LOW

PRESSURE COLUMN

EP-1 PUMP

PURGE _ECONOEP-1

WORKSTATION PUMP WASTE WASTE 6 7 1 2 3 4 5 AVR7-3 ECONO PUMP REAR PANEL SYSTEM CABLE 7 RED TO PIN #6 BLUE TO PIN #9 WORKSTATION REAR PANEL AUX UV CHART COND CHART UV OPTICS COND FLOWCELL SOLENOID VALVES MIXER 1 2 3 UV LAMP AUTOMATED VALVES INSTR. BUS 4 5 6 1. INJECT 2. n/c 3. n/c 4. n/c 5. FC ADV 6. AUX PUMP 7. n/c 8. n/c 9. GND 10..25V 0.3A MAX.

The EP-1 Econo pump can be used to load up to 7 samples sequentially when used with an AVR9-8 at the pump’s inlet valve, as shown below.

Figure 2-28. Example of Multiple Sample Loading using an Econo Pump 1 2 3 4 5 6 9 7 8 RINSE SAMPLE #1 SAMPLE #2 SAMPLE #3 EP-1 ECONO PUMP AVR9-8 AVR7-3 LOOP OVERFILL TO WASTE LOAD LOW PRESSURE COLUMN WORKSTATION PUMP WASTE ₆ 7 1 2 3 4 5

2.8.3 EGP Econo Gradient Pump

The Econo Gradient Pump (EGP) is a two-channel, bi-directional, variable speed peristaltic pump for low- pressure chromatography and general laboratory use. The EGP has the following features:

• The EGP can be programmed to run a gradient. • The EGP controls a splitter valve for stream splitting.

• The EGP may be used with most flexible tubing having an inner diameter less than or equal to 3.2 mm (1/8”), and a wall thickness of 1.0 mm or less, including Silicone, Tygon, and PharMed. • Flow rates are 0.01-20 ml/min per channel, depending upon tubing ID.

• It has start/stop control of fraction collectors and chart recorders. • It is coldroom compatible.

Figure 2-29. EGP Econo Gradient Pump

The EGP is connected to the DuoFlow Workstation with Bus communication cable (System cables 17, 18, 19, or 21). When the DuoFlow assumes control of the EGP, the EGP is automatically set to Remote mode. In Remote mode, the EGP keys provide limited control, allowing only basic observation of EGP operating parameters. For a complete discussion of the EGP, refer to its separate documentation.