15 minutes UV - (Nov/26/2008 )
Do you guys think that 15 minutes UV is good enough for sanitizing the cabinet ?
One evening i try to a aliquot a bottle of 500ml FBS into 50ml centrifuge tubes, but someone told me that i should do that at the morning, after overnight of UV sanitation. It is because FBS is very easy to be contaminated and many people have used the cabinet during the day, so it may have many contaminants.
I am new to cell culture. So i have no idea. Thanks!
New standards in lab safety points towards no utilization of UV for sanitizing cabinet. Too much risks for the benefits!
A good old 70% EtOH should do the trick.
But if you really want to use the UV, i think15-20 should be ok. And i'm relieved : when I saw the title of the topic, I thought you wanted to do a 15 min UV treatment to some cells. Glad its not the case 
My lab has done tests on this - areas exposed to UV in a hood will eliminate over 90% of the bacteria and viruses within 5 minutes and all bacteria within 15 minutes, the difficulty arises in areas which are not exposed to the UV properly. For this reason it is best to keep the hood clear of everything and wipe down with 70% ethanol before and after each user.
A good old 70% EtOH should do the trick.
But if you really want to use the UV, i think15-20 should be ok. And i'm relieved : when I saw the title of the topic, I thought you wanted to do a 15 min UV treatment to some cells. Glad its not the case
What are the risk of using UV actually? I heard that becuase of the high energy that will generate ozone. Is it true?
By the way, if i put FBS into the cabinet and switch on UV, will UV damage proteins inside the serum?
Thanks!
By the way, if i put FBS into the cabinet and switch on UV, will UV damage proteins inside the serum?
Thanks!
I don't know the first question.
Yes, I think UV will harm the component in FBS.
I don't think FBS will like solarium...it may get sunburn.
A good old 70% EtOH should do the trick.
But if you really want to use the UV, i think15-20 should be ok. And i'm relieved : when I saw the title of the topic, I thought you wanted to do a 15 min UV treatment to some cells. Glad its not the case
What are the risk of using UV actually? I heard that becuase of the high energy that will generate ozone. Is it true?
By the way, if i put FBS into the cabinet and switch on UV, will UV damage proteins inside the serum?
Thanks!
Using UVs is pretty dangerous because, as you may know, these kind of radiations do a lot of damage to DNA. So if you skin gets exposed, you may have sunburns, and eventually develop a melanome (we're talking extreme here, don't get freaked out if your only briefly exposed!). Moreover, UVs can seriously damage your eyes. Its pretty harsh
As I and other said, good'ol EtOH 70% is the safest way to go. But again, UVs can be used if done in a safe environment with apropriate warnings and protective clothing.
UV is damaging, but the vast majority of plastics and some glasses strongly attenuate the amount of UV that can get through, so I suspect that putting a tube with FBS/FCS under UV will not affect the proteins much, if at all.
The wavelengths of UV used in a typical class II hood are in the UV-C range, which are more damaging than UV-A and UV-B, but the amount of light put out by a hood is low enough that 20-30 min of exposure will give you a very mild sunburn (speaking from experience - malfunctioning hood). You will get more UV exposure by being outside on a sunny day for 15 minutes. Ozone generation by UV is unlikely as UV actually degrades ozone (remember the ozone hole over Antarctica, it is being scavenged by CFCs, but the way ozone acts as a UV protectant is that it breaks down into O2 and an oxygen ion/radical, which then combines with another oxygen ion to form more O2, thereby absorbing the energy of the UV to break the bond.). Anyway, the amount of ozone production by UV will be so small that it will be barely detectable and in a confined space that shouldn't escape, given the nature of the hoods.
One evening i try to a aliquot a bottle of 500ml FBS into 50ml centrifuge tubes, but someone told me that i should do that at the morning, after overnight of UV sanitation. It is because FBS is very easy to be contaminated and many people have used the cabinet during the day, so it may have many contaminants.
I am new to cell culture. So i have no idea. Thanks!
Oh dear here we go again
All the cabinet manufacturers have UV as an option BUT MOST DO NOT HAVE THEM AS A STANDARD AS THEY THINK IT IS INEFFECTIVE.
I have been doing TC work now for 29 years and have NEVER USED UV in all that time. The departments I have worked in have won a total of 2 nobel prizes and are considered to be in the top 10 of reseachers when looking at citations from the literature.
Using UV is a cop out in that it leads to bad practice
Cons of using UV:-
The bulbs need to be regularly changed...and are usually not
UV degrades TC plastic
It makes end users NOT CLEAN THEIR CABINETS EFFICIENTLY WITH VIRKON AND IMS
It will not cover the entire work surface
IT WILL NOT PENETRATE BELOW THE WORK SURFACE where the air flow passers over.
It is an expense.....IMS and Virkon are cheap options and are always required for GLP.
Pros:.............I cannot think of any
Just my take
Have just bought 60 odd class II cabinets for our Institute...and guess what NO UV and NO CONTAMINATION PROBLEMS IN OUR FIRST YEAR..
Kindest regards
Rhombus
If I can add something to the above very informative answers...
From what I've heard and read - first of all you should wipe the cabinet and everything you put inside with 70% EtOH + let the cabinet work for a while (about 30 minutes) - it will do the trick (it's the laminar flow of air itself that eliminates bacteria, etc. from the cabinet).
Use of UV makes people disregard other important safety steps.
But if you really need to use UV it's enough to let it work for 10 minutes.