Universal Vial Cap Construction Guide (Luer Connectors Only)

Universal vial cap with efflux tube in place.

Materials

• 3D printed (SLS, nylon PA-12) vial cap

  • Download the .stl file from GitHub

  • Order from Hubs

  • Get these "vapor smoothed" for better sealing

  • Get white nylon PA12 (the default black will leach dye into your media)

  • Other default settings are fine

• 4X - 3/32" female white nylon barb to luer lock

  • Buy at least 4 x number of caps + extra

  • Nylon required to survive autoclaving (expansion differential between normally used polypropylene and nylon 3D printed vial causes epoxy to separate)

• Semi-clear white hard nylon tubing (1/8" OD)

• Plasticweld epoxy

• [Required for overflow protection] Rubber stopper

• [Required for overflow protection] O ring

Construction Protocol

1. [Optional] Mark fluid lines on a glass eVOLVER vial (see below image)

   1. This will be used to set the efflux tube height, which sets the volume in the eVOLVER vial.

   2. Tape an eVOLVER vial

   3. Using a serological pipette, measure water into the vial in increments of 5 mL

   4. Mark the volume at each increment on the tape at the bottom of the meniscus

2. Using a razor, trim nylon tubing so that it reaches the volume you have set

   1. Nylon tubing will straighten in the autoclave, so try and straighten it out as much as you can

   2. Cut to 53 mm for 20mL

   3. Otherwise, determine the correct length using graduated eVOLVER vial from step 1

      1. Cut the tubing to a longer length than you need

      2. Pushing it into the vial cap until you feel a little resistance (easy to accidentally go further, but there is a stopping point)

      3. Screw the cap on all the way

      4. Estimate where to trim

      5. Check in vial cap again

      6. Measure length when you have this correct - use this for the rest of your vials (or use cut length as a guide for cutting the rest)

   4. Cut all tubing for the caps you are making

1. Use gloves when working with epoxy

2. Put epoxy into mixing tray and mix

   1. You don't need much because epoxy will likely set before you finish all vials

1. Apply epoxy to barb of luer connector

   1. Be generous, but avoid the opening in the barb

   2. If you do get epoxy in the opening, blow it out or pick it out with a paperclip

(Top) Connector without epoxy. (Bottom) Connector with epoxy on barb.

1. Press the connector into a port in the top of the cap, and twist a few times to spread epoxy

1. Repeat steps 4 and 5 for the other ports

   1. When epoxy starts to solidify, mix more (in a new tray)

2. Wait for at least an hour for epoxy to set somewhat

3. Epoxy one side of the outside of efflux tube (avoiding the hole)

4. Press the tube into left port of cap (when sampling port is facing you) (see below)

   1. Only press until you feel a slight resistance

   2. Twist once or twice to spread epoxy

Cap with efflux tube epoxied in to left port

1. Repeat steps 8 and 9 for all caps

2. Allow epoxy to set 24 hours before using