How to replace syringes, tubing and valves?

‍

‍

General Advice

• Always wear clean gloves or sanitize them with ethanol before handling syringes, tubing, or valves to maintain cleanliness.

• Ensure the system contains MilliQ water and does not have harmful substances before starting.

• Remove the valves from the Autofluidics unit before replacing the tubing.

• Handle threads carefully to avoid over-tightening them.

• Replace tubing and syringes after 6-12 months of usage to maintain optimal performance.

• Where to find the material: Tubing and syringes kit in the store

Tubing Material and Inner Diameter

• Material: FEP (Fluorinated Ethylene Propylene). Information on FEP's resistance to various liquids can be found here.

• Available Tubing Sizes for the u-Flux Unit:

• Small: 0.1 mm / 0.004" inner diameter – Used for channels 1–5, ideal for precious samples or low flow rates.

• Medium: 0.25 mm / 0.01" inner diameter – Typically used for channel 6; can also be used for channels 1–5 if higher flow rates are required.

• Large: 0.75 mm / 0.03" inner diameter – Suitable for channel 6 (e.g., waste) when medium-sized tubing is used for channels 1–5.

‍

Connecting tubing to valves

The following instructions provide instructions to assemble tubing to valves.

‍

‍

1. Use gloves + 1/16”  tubing, cut tubing with tube cutter, make sure it is nice cut vertical to tubing direction.
   ‍
   ‍
   ‍
2. Insert the tubing through PEEK screw.
   ‍
   ‍
   ‍
3. Add blue inlet with wide part towards the cut end of the tubing.

‍

‍

4. Make sure the cut end of the tubing is in plane with the surface of the blue inlet, tube not sticking out or forming a “hole”, otherwise liquid might get caught there.
   
   ‍
5. Put the whole assembly into the valve entry. Try to keep the tubing exactly where it was (cut end in plane with blue inlet surface).
   ‍

‍

‍

‍

‍

6. Turn the PEEK screw until cannot be turned anymore (tubing and blue inlet do not turn), this squeezes the tubing and blue inlet together.
   
   
   ‍
7. Once all is screwed in, the tubing the PEEK, and the blue inlet stay together, also when being unscrewed. This means that the PEEK cannot be turned without turning the tubing and blue inlet, as well.

‍

‍

How to disassemble tubing to valves

Use the instructions below to exchange tubing in new connector valve.

‍

1. To take the connection apart again, unscrew the PEEK screw. Note that now, you will not be able to turn it independent of tubing and blue inlet. This means that the tubing will start spiralling a bit by the amount you turn the PEEK screw, as long as the valve is fixed.
   ‍
   
   ‍
2. To remove the blue inlet and tubing, put your finger nail between the blue inlet and the PEEK screw. Hold the PEEK screw with your other hand and move the blue inlet relative to the screw. Exchange tubing/valve/clean/etc. + restart with assembly.

‍

‍Detaching and attaching the valve on the Autofluidics unit

Detaching:

1. Open the u-Flux applet or Bluelake on the computer.

2. Close all valves, and open the one that you want to detach.

3. Release the pressure from the fluidics.

4. Unscrew the screws of the valve.

5. Now you can take out the valve.

Attaching:

1. Open the u-Flux applet or Bluelake on the computer

2. Close all valves, and open only the one that you want to detach.

3. Release the pressure from the fluidics.

4. Make sure that the valve is physically open.

5. Put the valve back and screw in the screws.

Syringe type

Syringes (Terumo Luer Lock 3 mL syringe, see pictures below, take the plunger out before use) can be reused as long as proper cleaning protocols are followed. If syringes are permanently stained, very dirty or damaged, exchange them by just unscrewing them from the white teflon connection. For old systems, the teflon connections are sitting in the blue manual valve that is connected to the tubing.

Plungers of syringes can be kept in a clean box for manual unclogging of the tubing. When doing that make sure that the valve of your specific channel and the exit valve is open.

Making sure the newly connected tubing is leak free

To check the new tubing for leaks, add water (or any other non-harmful liquid) into all syringes. Make sure the liquid levels are equal. Start flushing with all channels and keep an eye on the liquid in the syringes, all syringes should show the liquid drop at an equal rate. If the liquid levels don\t drop at the same rate, please follow the troubleshooting guide below.

‍

Observation 1

Liquid level in syringe drops very fast (within seconds) and puddle of liquid appears under syringe.

Suggestion

Retighten the syringe into the white teflon part and retighten the white teflon part into the valve (older systems) or into the other white part of the connection (newer systems).

Observation 2

Liquid level in syringe drops faster than other syringes and puddle of liquid appears under syringe.

Suggestion

Retighten the tubing into the valve. To do this, unscrew the Peek screw, push the tubing 1 mm extra through the blue inset, and retighten the assembly. This means that the end of the tubing is not exactly flush with the blue inset, but sticks out a little bit. If this did not solve the problem, replace the blue inset with a new one.

Observation 3

Liquid is dripping from the metal part of the valves.

Suggestion

Follow the steps of observation 2. In case this did not solve the problem, replace the complete valve.

Observation 4

I see drops of liquid on the automatic valve unit, immediately under the bottom of the valve.

Suggestion

Follow the steps of observation 2.

Observation 5

I see a puddle of liquid forming around the connection of the vertical parts and horizontal part of the automatic valve unit (seemingly not near tubing).

Suggestion

Open the valve (without any pressure) using the automatic valve unit and use a hex key (size?) to unscrew the two bolts that hold the valve in place. Remove the valve from the automatic valve unit and clean up the liquid inside with something small and absorbent (e.g. a Q-tip). Follow the steps of observation 2. Test if there is still a leak by applying pressure and visually inspecting the valve without placing it back in the automatic valve unit. Only if the leak has been resolved, push the valve back into the automatic valve unit (while valve and automatic unit are both set to the ?open? position) and reattach it to the unit with the two bolts.

Observation 6

There is liquid on top of my flow cell.

Suggestion

Check if the outlet channel (waste/channel 6) was open during the time of flushing. If not, make sure it?s open first. If the problem persists, pull the tubing out of the flow cell holder and gently push the tubing back in to retry making the connection. If this still did not resolve the problem, check if the channel 6 tubing (exit) is completely filled with liquid and there is no air in it. If needed, fill the channel 6 tubing with liquid by pulling liquid out of an external container through with a syringe (use a white connector from your uFlux kit and make sure channel 6 is open in Bluelake).