How do I use the Pressure Application Device (PAD) and Pressure Syringe Kit?

The Pressure Application Device (PAD) and Pressure Syringe Kit (PSK01) help you wet a nanopore or chip, or clear a blockage, on the Exoid and Pulsoid. They apply pressure or vacuum to the fluid cell.

Included in the Pressure Syringe Kit:

• Pressure syringe tool fitting (sealing cup)
• 2 x 10 mL syringes

Once fitted together it is referred to as the “Syringe tool”.

Pulsoid

The Pulsoid has a built-in pressure system (APS) that applies pressure and vacuum through a pressure nozzle. The PAD and syringe tool give extra help, applied by hand, when the pore won’t wet or is blocked.

Use the PAD and syringe tool when:

• The pore isn’t wetting: there’s no current, or the corrected baseline current isn’t stable within the expected range for your chip (see Section 5.6 of the Pulsoid User Manual).
• The baseline current drops in steps or is unstable. This can mean the pore is blocked.

Step 1: Use the PAD

1. Place the PAD over the channel on the buffer side of the fluid cell to form a seal.
2. Press down gently, then pull up sharply.
3. Aim for a “pop” sound. This tells you a good seal has formed, and pressure and vacuum are being applied to the chamber.

Step 2: Apply pressure with the syringe tool

1. If the fitting isn’t already attached, screw the pressure syringe tool fitting onto one of the syringes. (In the Pressure Syringe Kit, the fitting is packed separately.)
2. Pull the plunger all the way up.
3. Place the sealing cup over the channel on the buffer side of the fluid cell.
4. Press down firmly on the sealing cup to make an air seal, then push the plunger in. A pumping motion can help.

Step 3: Apply vacuum with the syringe tool

1. Push the plunger all the way in.
2. Place the sealing cup over the channel on the buffer side of the fluid cell to form a seal.
3. Gently pull the plunger up, keeping the seal in place. No liquid should be pulled out of the channel. A pumping motion can help.
4. Gently remove the sealing cup, then dab it on a lint-free tissue to remove any liquid.

If it still doesn’t work:

1. Repeat Steps 1–3 once more.
2. If there’s still no or low current, remove the fluid cell from the instrument and tap it hard on a padded surface. Hold it so the fluid channel is at about 45° from horizontal, with the cavity side of the chip facing slightly up.
3. If there’s still no current, remove the chip and repeat Section 5.3 (Assembling the Fluid Cell) from step 4 onwards in the Pulsoid User Manual.
4. If the problem continues, replace the chip.

For full instructions, see Sections 5.6 (Establishing a Baseline Current) and 7.2 (Troubleshooting) in the Pulsoid User Manual.

Note: If you notice anything unexpected, such as liquid leaking from the fluid cell, or you can’t form a good seal (air escapes or gets in), stop and contact Izon Support.

Exoid

The Exoid has a built-in pressure system (APS) that applies pressure and vacuum through the pressure nozzle. The PAD and syringe tool give extra help, applied by hand, when the baseline is unstable or the nanopore is blocked.

Use the PAD or syringe tool when:

• The baseline current isn’t stable while wetting the nanopore.
• The nanopore is blocked: the RMS noise goes up, or the current drops below what you’d expect for the applied voltage.

Step 1: Tap the pressure nozzle

1. With the pressure nozzle in place, apply a pressure of +2500 Pa or −2500 Pa.
2. Firmly tap the top of the pressure nozzle with the back of the PAD.

Step 2: Plunge the upper fluid cell

If the baseline is now stable, stop here. If not:

1. Set the pressure to 0 Pa and remove the pressure nozzle.
2. Use the plunging end of the PAD to apply pulses of pressure to the upper fluid cell.

You can also use the syringe tool on the Exoid. It works the same way as the PAD, helping with wetting and unblocking:

1. Set the pressure to 0 Pa and remove the pressure nozzle.
2. Place the sealing cup over the upper fluid cell, where the pressure nozzle sits.
3. Push the plunger in to apply pressure or pull it up to apply vacuum.

For full instructions, see What is the nanopore wetting procedure and why is it important?

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