Cell culture and S2 work is always a hot topic.
Since it involves culturing cells and infecting them, the question naturally arises: what can and cannot be done sustainably in these environments?
The answer is – a lot. Even in S2 labs, significant amounts of plastic waste can be saved. I described one of my own workflows in detail in this publication (“Reducing plastic waste in scientific protocols by65% — practical steps for sustainable research”), but here are some key principles for routine work and those I have worked out with Jakob.
First, many doubt whether waste separation is even allowed. Legally, it is. The German regulation for genetically modified organisms explicitly states that waste can be discarded normally — and therefore recycled — if it has not been contaminated. The simple rule is this: everything that didn’t come into contact with genetically modified or hazardous materials can be separated.
That means, for example, the plastic and paper wrapping of serological pipettes can go into recycling rather than the biohazard bag.
Beyond disposal, there are small but impactful tweaks in daily handling. If you are splitting one cell line into several flasks, you can reuse the same serological pipette to distribute medium across them. Choosing larger pipettes when working with only one cell type – for example, dispensing PBS or trypsin in one go – also reduces pipette use. For some cell lines, culture flasks can even be reused for routine maintenance, provided you check carefully that the cells remain healthy. And when working with small flasks, adding medium first and then cells means one serological pipette can be used for both steps.
Safety, however, is non-negotiable. Jakob, for example, never reuses serological pipettes or shares them between parallel splits when handling two different cell lines. This eliminates any risk of cross-contamination, which would be nearly impossible to detect later if a few stray cells started growing in the wrong culture.
As always, you should only go as far as you feel comfortable. Implement controls, pay attention to best practices such as expelling liquids completely, and above all, gain sufficient experience before attempting to adapt. Experience is what allows you to judge whether a practice is safe or not. Even then, the transition should be gradual. Make small changes step by step, so that you can keep your flow without becoming insecure, and so you can trace what works well and what doesn’t.
And remember: if you are in a hurry, don’t force sustainability into the workflow — that’s when mistakes happen. Finally, culture matters. How do you communicate what you expect from your lab members? Make sure postdocs and PhDs are aligned and that sustainable practices are included in training. When new colleagues join, take the time to let them shadow for two or three sessions so they learn the lab’s culture of working. Having someone look over a shoulder is often enough to correct habits, catch overlooked opportunities for optimization, and make sustainability part of the lab’s shared standard.