I am new to this messaging board. My lab is considering adopting lab automation. We are an immunology lab with several drug screening projects where we add different compounds to immune cell cultures and incubate for 1-2 weeks. We want to use the Prep to pre-aliquot drug compounds from a stock plate into diluted plates with cell culture media which we then freeze and later add to cell cultures.
One question we’ve been wondering about is how essential the HEPA filter is in this setting. Our media contain antibiotics, and the Hamilton prep is enclosed in a case, so I expect very little airflow during the actual automated pipetting. Of course, gravity can cause particles in the air to drop over time. However, the HEPA filter comes with a quite steep price tag, so I was wondering if anyone has any opinions or experience with this. Has anyone used the prep in a similar setup without a HEPA filter?
The ML Prep has a cooling fan for the electronics that is constantly pulling air through it when running. I’d think this would pull in enough from the surrounding lab air to cause issues. The Prep-CAP HEPA fan is designed to overcome this and keep the inside clean.
I would assume it’s necessary to maintain sterility, and unless you have a pretty hefty and constant cleaning protocol you run the risk of issues.
That being said, I’m sure it’s been done in a situation similar to yours without a HEPA filter, if you are able to get a biobubble (pricey) they are great as well - https://biobubble.com/products/enclosures-for-robots/.
I’d decide based on your risk tolerance for non-automated bench work and tissue culture. Are your scientists strictly handling all reagents and materials that go into cell culture inside a biosafety hood? If not, then you probably don’t need to apply that level of stringency to a robot.
There’s certainly processes where that level of risk aversion is warranted, but it depends what your own tolerance level is.
Thanks, everyone — that’s really helpful information. Based on your comments, it seems that some kind of clean environment will likely be necessary. I saw on the Hamilton website that some users have placed the Prep inside a biosafety hood.
Does anyone here have experience with that setup? Does it effectively address the cleanliness concern?
I’m wondering how much benefit the biosafety hood actually provides in this case, since its filtered air flows downward — but the Prep has a glass ceiling, which might block that airflow from reaching the deck.
Do you think placing the Prep inside a biosafety hood is enough to maintain a clean environment similar to manual work in a biosafety hood? I realize there may not be a definitive answer, but I’d appreciate hearing your thoughts.
Do they make biosafety cabinets that big? I think the point of the HEPA is to turn the Prep into a biosafety cabinet, essentially. The air flow in a biosafety cabinet is meant to maintain positive pressure so that contaminants don’t flow inside, as far as I know/
For Preps being put into a larger biosafety hood, there is a kit available that allows the enclosure to be removed plus a different/extended wiring harness for the touchscreen.
Congratulations on your potential adoption of lab automation! I wanted to share my experience with automated cell culture, both in HEPA-enclosed systems and setups without a HEPA filter.
Surprisingly, in two different platforms (a STAR and a Biomek i7), we were able to successfully maintain cultures without a HEPA filter, with minimal contamination (just one or two cases over six months). In both cases, antibiotics were used, and in the Biomek system, cultures were maintained for up to 10 days.
I think a key point is maintaining cleanliness; we wiped our systems with Microside SQ or 70% ethanol before each use. While I definitely do prefer having a HEPA filter, as you note, they can be pricey. Also worth noting, the HEPA filter alone does not guarantee sterility, building wholistic systems to reduce potential contamination points is key.
Best practices for automated cell culture could make for a great thread on its own. Wishing you the best of luck!
Depending on how toxic the drugs you are working with (and how your safety department would want to deal with that), you may want to consider the implications of various strategies.
If you buy the HEPA unit and place the system on the bench, you are going to be protecting your samples from contamination, but not protecting the operator in that case (air being pushed out to operator in a positive airflow direction. If the drugs are very low concentration or are not considered toxic, then this may be less of an issue.
If the drugs you are working with are toxic, then you may want to take a look at this thread where the use of formaldehyde and protection from its fumes was discussed in greater detail.
Most places you can use a “minute” or “small” amount of toxic chemicals in a Biosafety cabinet, but remember that while this doesn’t push air out to the operator, the Biosafety cabinet isn’t really filtering any toxic chemical; it will recirculate in the hood and eventually exhaust out to a vent somewhere (hopefully filtered appropriately somewhere else in the house HVAC system). If you currently do this work manually in your Biosafety Cabinet and your safety team has approved that, then this might be your best bet.
Removing the enclosure as @mrthorne recommends is a good idea to help with airflow. But depending on the Biosafety cabinet you have, you will need to verify that it can maintain a proper airflow once its placed in there (make sure that airflow coming into the Biosafety cabinet in the back is not blocked too much).
There are other ways to deal with this (enclosures with negative airflow and carbon filters), but that can quickly become a very expensive and complicated endeavor. The thread here previously focused on contamination protection, so I wanted to ensure that you are thinking about operator safety too. Hope this helps!
Hi everyone, thanks so much for this incredibly helpful feedback. There is a lot to consider for us now but based on your thoughts and comments, I am confident that we will be able to make an informed decision now. Overall, i guess the perfect system does not (yet) exist and we’ll likely have to balance drawbacks vs. benefits (as is always the case ˆˆ).
Overall, i guess the perfect system does not (yet) exist and we’ll likely have to balance drawbacks vs. benefits (as is always the case ˆˆ).