Blog by Dr. Isobel Taylor-Hearn

In the race for scientific discovery, the environmental cost of research is often overlooked. Labs worldwide rely heavily on single-use plastics and follow legacy practices, prioritising convenience over sustainability. Yet, as the climate crisis intensifies, balancing efficient research with ecological responsibility has never been more important. Encouragingly, some laboratories are paving the way toward a greener future by making small but impactful adjustments to their protocols, without compromising scientific quality. 

One program that supports this shift is LEAF (Laboratory Efficiency Assessment Framework), which offers a toolkit of actions for labs to save plastics, water, energy, and other resources. Through participation in LEAF, laboratories reduce their carbon emissions and cultivate an environment that supports both sustainability and high-quality research. Labs are audited as part of the program, allowing them to assess their practices and uncover ways to improve further. These audits also provide a valuable opportunity to share green practices across the university. 

A shining example of these efforts is the Dixon Lab, based at the Manchester Institute of Biotechnology. The team identified that 50ml plastic Falcon tubes were among their most frequently used items, averaging about 480 tubes each month. Primarily, these tubes served as mini-bioreactors for growing small volumes of bacterial cultures. After hearing about good practices in the neighbouring (Cai) lab, the Dixon Lab’s technician Ruth Perez spearheaded a campaign to replace the single-use tubes with a reusable glass alternative. The lab has now implemented a system to wash, dry, and autoclave batches of glass tubes to maintain a steady supply of sterile tubes. 

Ruth told us that the “Dixon Lab members were very supportive and willing to try the new set-up out for themselves.” Indeed, the switch has been well-received and adopted by all lab members, with no negative impact on their experiments. Qin Qi, a postdoctoral research associate in the Dixon Lab said that;

“The use of glass bacterial culture tubes has allowed me and my lab mates to make a positive contribution to sustainability while reducing lab spending on single-use consumables. The transition from single-use Falcon tubes to reusable glass tubes has been a very smooth process thanks to a set of SOPs that are robust and easy to follow.” 

Micaela Chacon, another postdoctoral research associate in the lab, reported that;

“The switch to glass test tubes has been a positive change for our lab, with notable improvements in microbial growth due to the improved aeration. The durability and reusability of the glass tubes has reduced our overall plastic waste, which has been both environmentally beneficial and cost-effective. This shift has also highlighted the volume of plastic waste typically generated in biological research, encouraging us to explore further sustainable practices in the lab.” 

Although plastic Falcon tubes are still used for centrifugation, where glass alternatives are unfeasible, the lab estimates they have reduced their tube use by approximately 200 tubes/month, generating real environmental and financial savings. 

It’s important to consider the full lifecycle—or “cradle to grave”—of lab consumables when evaluating sustainability. This includes not only manufacturing and transport but also the energy,  water and detergents required for washing, autoclaving, drying, and eventual disposal. A recent study, based on a setup similar to the Cai lab, assumed labs had a one week supply of items, which were washed and dried in batches. The paper found that single-use Falcon tubes generated 11.3 times more CO₂ equivalent than reusable glass alternatives, even after accounting for washing overheads and a 10% breakage rate. Another recent study estimated that each polypropylene Falcon tube (weighing approximately 13g) has a cradle-to-grave carbon footprint of around 54g CO₂e—this accounts for emissions from raw material extraction through to manufacturing, transport to the consumer and subsequent autoclaving and low temperature disposal. Based on these figures, the Cai lab’s small change has led to an annual saving of 2,400 Falcon tubes, more than 130kg CO₂e (equivalent to an average petrol car driving 747 km), and around £250.  

LEAF auditor and PhD student Jeremy Dejardin was keen to share what he’d seen in the Dixon lab with his own group: 

“I was very impressed by the Dixon lab’s take on the traditionally single-use items such as the culture tubes and electroporation cuvettes, the former being used almost daily in our lab. Simply switching these two items would greatly reduce our use of single-use plastic, and protect us from the occasional supply shortage.” 

By making this change, the Dixon Lab exemplifies how small shifts in lab protocols can lead to substantial reductions in plastic use, contributing to a greener scientific environment without sacrificing research integrity. Their journey is a reminder that sustainable science is possible, one small adjustment at a time. If you’re interested in adopting a greener protocol for overnight cultures, please find an example below. If you and your lab use any other green protocols, please let us know by emailing srbmh@manchester.ac.uk.  

Green SOP

1. Prepare liquid LB with DI water and autoclave 

• Eco tip: Only make up enough LB for the cloning you have planned! It’s unlikely you’ll use >400ml before expiring so don’t make up more than that! 

• You can do this by adding individual components or using pre-mixed LB agar powder

2. When the liquid LB is cool to the touch, add the appropriate antibiotic to the correct concentration 

3. Add the desired amount of liquid LB to a tube or flask  

• Maxi prep: 60ml broth in a glass flasks. Use tinfoil to cover the flask and seal (loosely!) with tape 

• Mini prep: 2ml broth in a tube  

• Eco tip: You can use glass tubes (see details below) and sterilise them between use 

4. Using a sterile pipette tip or toothpick, select a single colony from the agar plate (try not to stab the agar, just get the colony) and add it to the LB (add the whole pipette tip!) 

• For maxi preps (flasks) – use tinfoil to cover and tape the flask 

• For mini preps (glass tubes) – use the lids listed below, which are not airtight 

5. Add the tube/flask to the shaker and shake for 16-18h at 37°C 

• Eco tip: Can you share shaker runs? Can you share the shaker with neighbouring labs (maybe start a booking system) so that the shaker isn’t running <½ full? 

6. After incubation, check for growth. You can tell you’ve been successful if the broth turns cloudy 

7. You can now isolate your plasmid DNA from the bacterial culture 

Cleaning and Disinfecting Glass Tubes 

1. Add 1% Virkon to cultures and leave for >1hr 
2. Rinse tubes in water and use a bottle brush to remove debris if needed 
3. Place tubes (face down) and caps in baskets and take them to the dishwasher 
4. Select “volumetric wash” mode on the diswasher 
5. Send tubes and lids for autoclaving 

Calculations: 

Saved 200 tubes per month 

200 tubes/month x 12 months = 2,400 tubes/year = 8 boxes of 300 tubes = £213.60 – £279.36 

Without polystyrene £26.70 

With polystyrene £34.92 

1 PP Falcon tube weighs 12.9g  

Cradle-to-grave CO2e of 1g PP when autoclaved and disposed of at low temperature is 4.2g -> 1 PP Falcon tube has a cradle-to-grave CO2e of 54.18g when autoclaved and disposed of at low temperature 

The average petrol car emits 174g CO2e per km 

2,400 tubes/year =  30960g PP -> equivalent to 130,032g CO2e -> equivalent to 747km travelled 

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