Does anyone have any recommendations for extra long needles and septa for applications requiring gas exchange, using the typical 40mL chemglass borosilicate vessel?
We’ve recently been 3D printing nylon mounts that enable the vessel to interface with more liquid/air inputs that have been generally useful for use in eVOLVER:
These mounts are designed to screw onto the typical 40 mL glass vessel. You can either use them with a silicone septa or without.
Without a Septa
Running the system without a septa is more convenient and sterility hasn’t been an issue in our hands (even with the sampling port on the top). I would recommend using 1/16" PEEK tubing to be threaded through the holes. PEEK tubing is polymer based, very resilient, rigid, and inert. This is a great choice for defining the volume of the culture vessels (efflux length) and also has the added advantage of not rusting (whereas needles might rust over time).
With a Septa
Adding a septa helps in conditions where sterility is more of a concern (mammalian cell culture) and gas control is important. However, this makes sampling more difficult and you would need to use needles to interface with the culture vessel.
I typically cut a small piece off the septa with a razor blade where the sampling port is to make it easier to sample with a pipette tip. Additionally, this helps vent the vessel and prevent pressure build up.
Input needles/ Venting Port
You can choose what length best fits your application