Though scientists are exceptionally smart and resourceful people, they aren’t always the neatest. I’ve walked into many labs where the area around the weigh scale is littered with unidentified powdery substances and the sink is full of unwashed labware. Unfortunately, cleanliness is extremely important in the lab, as chemicals and microorganisms can quickly contaminate freezers, benches, and incubators if not kept properly cleaned, making the lab a potential danger for both you and your samples.
#1 – Schedule cleaning time
Working in the lab can be hectic. While scheduling cleaning can be inconvenient, all your hard work will be for naught if samples keep getting contaminated because the lab is dirty. To make the most of your time, you can plan lab clean-up hours using a laboratory information management system (LIMS). A cloud-based LIMS can efficiently manage many aspects of your lab, including workflow, inventory, and results analysis; it can also regularly schedule hours for cleaning far in advance, allowing you to assess your lab’s cleaning requirements and assign members of the lab to specific cleaning-related tasks as needed.
#2 – Do it regularly
Cleaning regularly makes your lab both efficient and safe. One thing that can drive a scientist crazy is needing to use a station that someone else operated without cleaning up after themselves. This is particularly dangerous, especially for weighing stations, as any leftover chemicals, in the form of liquids and powders, can harm others who need to use the space after. But it’s not just basic cleaning that needs to be performed frequently; make a weekly schedule for each area that needs to be washed, including dusting benches, emptying biohazard waste containers used in biosafety cabinets, and any other equipment maintenance that’s needed.
#3 – Use the right tools
It’s important to use the right cleaning solution for the different items in your lab. In general, most labware should be washed with detergent and water in the sink immediately after use to prevent buildup of residue. Some chemicals, such as insoluble organic solutions, don’t just need water and soap; they also require rinsing with ethanol or acetone to completely remove any remaining deposits. To eliminate bacterial, viral, or fungal contamination, ethanol or bleach sprays can be applied to almost any surface. Some labs use specialized products, like Oosafe®, to decontaminate, which is recommended for in vitro fertilization (IVF) labs due to the low levels of volatile organic compounds Oosafe emits. For radioactive substances, special sprays are available that absorb the contamination, such as Alconox, while RNase and DNA contaminants can also be eliminated using specialized cleaning products (e.g. RNase AWAY and DNA AWAY).
Here are a few other specialized methods that can be used to clean labware:
- Batch sterilization – Many types of batch sterilization methods exist, though most lab consumables and glassware can be sterilized by steam autoclaving at high temperatures and pressure. Medical equipment, such as catheters and stents, can only be sterilized by ethylene oxide gas, while products like medical devices and pharmaceuticals require gamma irradiation. Remember that sterilization only eliminates microorganisms and won’t remove chemical residue from your labware. It’s also important to use sterilization-resistant labels here, as other types of labels may fail when exposed to high heat and pressure, gas, or gamma radiation.
- Dishwashers – Laboratory dishwashers are specialized to prevent cross-contamination between the wash and rinse cycles. They use relatively high temperatures to clean glassware and often include accessories designed for specific types of labware, such as test tubes, petri dishes, and pipettes.
- Ultrasonic cleaners – These cleaners use sound waves to remove dirt from glassware. The sound waves can be combined with solutions that help remove particles. Solutions that are flammable or that have low flashpoints should be avoided when using ultrasonic cleaners as energy buildup can cause them to ignite.
- Pipette cleaning – Reusable pipettes can be cleaned either in a plastic jug that continually fills and siphons water, washing and rinsing the pipettes or using direct injections baskets, which allow direct injection of water and detergent, followed by a heated rinse. Handheld pipettes can be cleaned by dismantling them, replacing damaged or old O-rings, and rinsing individual parts with appropriate solutions.
#4 – Get rid of old reagents and samples
When you’re cleaning your lab, it’s worth ridding yourself of all the degraded samples and spoiled reagents that are only attracting more dust and clutter. If you’re unsure what samples need to be thrown out, you can always refer to your LIMS (or your handwritten lab books) to determine how long they’ve been stored. For reagents, you can even schedule dates for disposal in your LIMS during the preparation process.
#5 – Defrost your freezers
How many times throughout the year do you open the freezer only to see ice covering the entire series of shelves, making it impossible to remove sample boxes? Freezers should be cleaned out on a regular basis for two reasons: it makes obtaining samples easier and it saves on energy costs, as excessive ice means the freezer needs more power to maintain a uniform temperature. This task should be performed routinely, ensuring that freezers don’t build up large ice deposits. When defrosting the freezer, make sure to set up bins at the bottom to collect the water that will inevitably form as the ice melts; walking into the lab to find it flooded the next morning is never fun.
Cleaning the freezer also presents the perfect opportunity to organize your various racks, boxes, and other containers. Whether they have non-cryo labels that fell off or were never labeled in the first place, now is a great time to properly identify your frozen inventory. Fortunately, the boxes and samples can be labeled without defrosting them. To do this, there exist labels, such as CryoSTUCK®, that can adhere to previously frozen surfaces, making re-labeling these frozen boxes or samples possible without the risk of degrading what’s inside.