Hi everyone,
I’m not sure if it was discussed before, but I am curious about your experience with pipetting through septum-push cap tubes using a disposable tip liquid handling system.
I’m considering using a customised adapter to hold the tubes more securely on the rack, but I’m still worried about the tips getting stuck in the septum.
Any tips or suggestions on how to handle this more smoothly?
I have only ever used fixed tip Tecan systems for pipetting through a septum and would hesitate strongly if I ever was required to do the same with disposable tips. Are we talking about ~1mL tubes? Or larger 4mL vials with septum tops? What automation system will you be doing this with?
For 1mL tubes on a Tecan system I don’t imagine this would go well with DiTis. Even with fixed tips we some issues, but that was mostly around alignment issues. DiTis would only exacerbate those issues, plus have others with tips trying to pull off the cones as you exit the septums.
Hi @jnecr,
Thank you for your answer. In our case, we’re working with 1–2 mL tubes, and we don’t have a specific system in mind yet. I am just exploring best practices for this type of application.
Did you use pre-slit septum caps in your setup?
Yes, we were using Abgene 1.2mL tubes with a pre-slit septa cap. Systems were all Tecan with fixed tips, 1mL syringes for liquid displacement pipetting. Even if they made fixed tip AirLiHa systems I don’t believe they would have worked very well. The septum would frequently create a bit of a seal around the tip creating a small vacuum as you aspirated liquid from the tube. This wouldn’t play well with an air displacement system.
We had two methods of “stripper plates.” One was to have a plate that was attached to the LiHa itself and stayed at a designated height right above the level of the tubes. As the tips retracted from the tubes the stripper plate would keep them in the rack. The other method was every tube rack sat under stripper plates, achieving the same thing. Looking back I think the first method was more elegant.
We were storing DMSO solutions for HTS, the Tecans used DMSO as the system liquid, so cleaning the tips was easy. Rarely did we ever have carryover issues, when we did it was hyperpotent compounds for very certain projects. We had to handle those on different systems. Otherwise we probably had 7 or 8 million tubes across 3 sites doing this process. Worked pretty well.