Reducing waste
Reducing plastic waste within the laboratory can be achieved by:
- Optimizing protocols to prepare solutions in a single instead of separate tubes
- Using items in a smart manner by rethinking their application possibilities (e.g., mixing loading dye and samples for agarose gels after kit use on a piece of parafilm or within a reusable mixing plate instead of separate tubes)
- Using alternatives such as glass or metal items for flasks, dishes, and serological pipettes)
- Minimizing the size of consumables (especially tubes, serological pipettes, pipette tips to the required volume, potentially pipetting twice)
- Optimize for the least necessary conduct (e.g., leaving out parafilm when evaporation of fluid is not an issue)
- Pouring solutions where precises volumes are not decisive (e.g., washing steps)
- Reusing Falcon tubes, potentially after rinsing, especially for frequently used solutions (e.g., Tris solutions when preparing SDS-PAGE gels)
- Reusing pipette tips, tubes where cross-contamination is not an issue (e.g., pipetting samples in agarose gels to control for restriction digests)
- Reusing items (e.g., electroporation cuvettes or tissue/cell strainers after cleaning, cuvettes for OD measurements, weighting boards)
- Precise calculation and bulk preparation of reagents and solutions
- Automatization and miniaturization through automated systems which pipette more precisely and are less error prone
- Conscious use of gloves (see our previous lesson to learn all you need to know)
- Using items to their capacity (e.g., maximize use of wells in a 96‑well plate, all targets on an MS plate or both ends of a toothpick to pick colonies instead of pipette tips)
- Sharing items and resources to their maximum potential (e.g., parts of unused agarose gels can be kept in buffer for up to 1 one week to be used for general PCR or restriction digest controls)
- Purchasing only what is necessary (tubes without caps, DNA/RNA extraction kits without collection tubes)
- Making use of take-back programs for plastic items, including Styrofoam
- Separating waste into plastic, paper, others, autoclavation (e.g., plastic wrapping from serological pipettes tips can be discarded in plastic and paper after separating instead of autoclavation waste bins)
- Consider reuse instead of discarding (Polystyrene boxes can be used as ice boxes or to fill empty spaces in cold storage, Packaging can be used to send reagents or samples to other laboratories, Polystyrene can be used to store glass items safely)
-> Cool Examples from my consulting:
The idea of using a pipette tip to spread colonies was passed down from an Asian scientist to a postdoc, just as it was to me. Pro tip: it works best with a P200 tip – a P1000 is often too large.
The same group reused their electroporation cuvettes up to 50 times – basically until the plastic turned yellow and brittle. Their washing procedure: 1× water (to prevent DNA precipitation) → 1× ethanol → 1× water → 2× desalted water → air drying → UV for 20 minutes.
Improving experimental conduct and design
- Proper experimental planning can be achieved by:
- Leveraging existing literature to avoid redundant experiments
- Robust statistical planning (especially power analysis to assure interpretable outcomes) help reduce sample sizes and enhance statistical validity (e.g., group sequential design for work entailing animals)
- Carefully chosen experimental conditions with proper controls (e.g., using painkillers with known mechanism of actions for control conditions)
- Reducing use of animals by switching to in vitro / in silico or smart experimental design (e.g., reducing breeding through smart knock out/in strategies)
- Re-optimizing protocols that were tailored for a specific tissue/sample/chemical
- Reviewing possibilities for optimization in consumable utilization ahead of conduct (including material, size and number of consumables)
- Exploring preparation procedures (e.g., optimizing pipetting schemes and master-mixes to reuse tips and tubes)
- Optimization of experimental produces is possible through:
- Adopting safer and more benign alternatives for commonly used reagents in experiments (e.g., DNA staining solutions, microscopic slide mounting agents, lysing agents, or protease inhibitors)
- Exploring alternative experimental approaches (e.g., using Supercritical fluid chromatography to avoid organic solvents needed in HPLC or modes of inducing cell death)
- Applying combination methods such as LC-MS to minimize sample preparation and maximize data acquisition
- Switching to miniaturization procedures (automated pipetting, solid phase microextraction (SPME))
- Best practices for experimental conduct include:
- Considering potential for downstream use or regeneration (e.g., regeneration of nucleic acid extraction columns)
- Minimization of experimentation (e.g., reducing PCR volumes to 10uL instead of 20uL if the overall presence of a construct or the success of a digestion should be assessed)
- Implementing strategies and frameworks to ensure best practices (e.g., handling pipettes upright when pipetting)
- Awareness of toxicity of reagents in use for proper handling and discarding (e.g., including closing lids to avoid evaporation)
- Impact can be reduced by initiating collaboration with:
- Colleagues in co-preparation of solutions, sharing of samples or co-use of machines (e.g., water baths)
- Other groups to share equipment
- Core facilities or partners to avoid unnecessary establishment of new methods
-> Cool Example from my consulting:
One of the scientists decided to use larger 2 mL tubes instead of 1.5 mL tubes. The reason: since the 2 mL ones have a round bottom instead of the conical shape of the 1.5 mL tubes, he could resuspend the pellet by vortexing without needing a pipette. Additionally, he could pour off the supernatant after centrifugation without needing to pipette it out, since the larger surface ensured the pellet adhered to the bottom. In doing so, he saved two tips and quite a bit of time.
Changing procurement and purchasing processes
- Planning orders carefully by:
- Creating an internal system to track chemical inventory and consumable supplies to minimize unnecessary orders
- Reduce frequency of orders
- Collaborating with other laboratories or facilities to collect orders
- Contact manufacturers to organize more efficient delivery and packaging
- Choosing products consciously by:
- Procuring items in quantities aligned with future usage (i.e., not more than necessary but in bulk if possible)
- Purchase large quantities (e.g., NaCl or bacterial/fungal medium components)
- Emphasizing sustainable packaging practices, favoring minimal material usage and biodegradable materials where possible
- Opting for specific shipping methods and alternatives to conventional cooling methods (e.g., when ordering polymerases without cooling or oligos dry)
- Choose products of lighter weight (e.g., gloves, tubes, pipette racks)
- Choose products that have exchangeable parts (e.g., vacuum filters in which just the filter is exchangeable instead of the entire plastic housing is single use)
- Thoroughly evaluating feasible alternatives based on certifications, life cycle analyses, and sustainability practices
- Choosing the optimal supplier:
- Preferring local suppliers to reduce transportation-related emissions and dependency on global supply routes
- Preferring certified suppliers and articles
- Exploring take-back programs and consider second-hand purchases to enhance sustainable procurement practices
-> Cool Examples from my consulting:
To prepare their medium, a group originally used a plastic filter top (125 g) and a dedicated plastic bottle (75 g), both of which had to be discarded after a single use. Recently, they found a reusable filter top where only the filter itself needs to be replaced — they simply buy the correct diameter and pore size from Merck and use glass bottles for filtration.
They also showed me a very useful 96-well PCR plate with a silicone sealing mat, allowing both pieces to be washed and reused for routine PCR checks.
Reducing paper, water and energy use
Paper
- Transition to digital sources like electronic lab journaling and online publications
- When printing is necessary, using recycled paper and opt for double-sided printing on previously used paper
- Practice conscious use of wipes (i.e., avoid stacking of unnecessarily many wipes)
- Reuse wipes (e.g., when drying slides)
Water
- Minimize water use, for example by soaking steps and mechanical cleaning
- Consciously discern water types (tap, distilled, double distilled etc.)
- Use only as much ice as needed
- Ensure proper maintenance of equipment (e.g., filters of reverse osmosis systems)
- Choose proper equipment and use (e.g., medical grade sterilizers are often designed to run 24/7, exceeding needs in common laboratories and Switching from traditional steam-jacketed autoclaves to newer types without steam jacket)
- Install Low-Flow Aerators
- Reusing “Wastewater” (e.g., institution wide when high grade water is reused for less curcial tasks or with counter-current rinsing principles)
- Choose waterless equipment (e.g., waterless condensors)
- Avoid Single-Pass Cooling Systems by using Closed Loop Systems
- Consciously choose batch-type washers versus tunnel washers depending on your usage
- Consider automated systems to provide only the necessary amount of water for animals, reducing waste while maintaining animal welfare.
- Install high-efficiency wet scrubbers that minimize water use while effectively controlling emissions
- Reduce the frequency and volume of hood wash downs by adopting targeted cleaning practices and evaluating actual cleaning needs
- Implement water recycling and treatment systems to reduce the overall water demand of cooling towers
- Optimize settings and capture HVAC condensation water for non-potable purposes, such as irrigation or cooling tower makeup water
- Actively search for and report leaks in taps and pipes
Energy
- Regularly organizing and cleaning digital inboxes to prevent unnecessary data storage
- Maintain a tidy system for experimental data, avoiding unnecessary duplication and keeping a safety copy securely stored on a hard drive
- Exercise caution with AI technologies and use of search engines due to their potential high energy consumption
- Evaluating the necessity of video in online meetings and switch to audio-only when possible to minimize data and energy usage
- Keeping laboratory fume hood sashes shut and turn machines off when not in use (e.g., water baths)
- Double check A/C settings and location of thermostats to avoid unnecessary cooling due to exhausted air
- Reduce air exchange frequences in HVAC systems if possible
- Set up an organization software for people to coordinate use & turn on/off of equipment
- Search for new innovations and energy efficiency when purchasing new equipment (i.e., lower energy usage e.g., in freezers or HPLC systems, choosing LED instead of halogen using microscopes)
- Create concrete plans/responsibilities for light & equipment turn off during weekends and vacation
- Optimize equipment placement (e.g., move freezers away from walls to allow for proper heat dissipation and consider how many and which pieces of equipment shall be placed in a single room)
- Setting PCR-Holding Temperature to 12°C or higher
Optimizing Equipment Use
- Choose instruments with reference to:
- Lifetime (e.g., photomultiplier tubes have longer lifetimes)
- Capacity (e.g., volume of sterilizers & autoclaves)
- Components (using low-boiling-point solvents in air-cooled condensers to reduce energy consumption)
- Minimizes reagent use (e.g., Nitrogen consumption in MS or HPLC columns with smaller inner diameter to reduce solvent consumption and waste creation)
- Performance (necessary precision, combination methods such as LC-MS reduce sample preparation)
- Running mode (e.g., enables change to more sustainable alternatives (Hydrogen as carrier gas instead of He in GC/MS) or enables internal reuse (e.g., automated recycling of the mobile phase for example after absorption of the impurities)
- Making a conscious choice about what methodology to use (e.g., wet vs dry blotting, on site analysis, high throughput analysis, combination techniques such as LC-MS)
- Exercising best practices (e.g., not let elution fractions from chromatography columns evaporate or using all spots on matrix array plates for MS, putting as many samples on one microscopy slide as possible)
- Being aware of the robustness of methods (e.g., ability to reuse TLC capillaries after rinsing)
- Reducing energy use by:
- Developing an energy plan, i.e., when to turn on and off individual machines
- Using strategies like multi-plugs to turn off ovens and water baths during inactivity or employing smart plugs for automated on/off cycles
- Considering carefully how you use equipment (settings including scanning area in microscopy)
- Modifying freezer temperatures, such as increasing from -80 to -70
- Using covers for water baths and replace oil baths with more efficient alternatives like metal heating blocks or efficient oil pumps
- Operating dishwashers and autoclaves only at full capacity
- Consciously choosing levels for the A/C set-up
- Choosing sufficient settings (e.g., temperatures and shaking frequency in incubators
- Disconnect ducts of fume hoods in which non-toxic chemicals are use
- Hibernate no longer used fume hoods in order to save energy since they are normally included in the general ventilation system
- Hand over, use secondary market or donate equipment that is no longer in use
- Reducing water use by:
- Implementing low-flow aerators to conserve water
- Using closed-cycle cooling systems and waterless liquid-cooled condensers with low-boiling-point solvents as an alternative to single-pass cooling methods
Optimizing waste treatment
- Making sure that evaporating waste is handled properly (e.g., stored in a hood or closed container)
- Using old jerry cans/flasks/container as waste containers (or already contaminated tubes)
- Create a plan how to handle cooling packs, animal bedding, Styrofoam etc
- Establishing education and indication systems (e.g., easily undersandable stickers on waste bins, using and a database with necessary educational resources)
- Repairing broken glassware (e.g., through chemistry faculty internal gaffers) and old pipettes
- Proper separation of waste (e.g., paper vs plastic, contaminated vs not-contaminated)
- Identify biosafety and contamination sources to avoid unnecessary contimation (e.g., in some institutions, all items touching a bench count as contaminated, thus, de-wrapping packaging outside the lab avoids autoclavation before recycling)
- Separate items early on (e.g., when caps of tubes are not used, they can be discarded in common plastic trashes)
- Create robust recycling schemes in cooperation with 3rd parties (i.e., developing separation schemes in HDPE vs PP that actually are maintained in transport and recycling by the waste handling parties)
- Ensure buy in from all stakeholders when it comes to waste separation (especially cleaning staff and waste handling parties must be informed and screened)
- Try to compost biological materials or animal bedding