I’m a Virologist - AMA

[LaserMicroscope]

I can’t promise answers to every question to everyone’s satisfaction (because some things we don’t know yet) but if for some reason you have a virology related question, please feel free to ask.
Cheers

 

[Encap]

LPF is a laser fourm, not a virus forum, the "General" forum is for Laser and laser related posts not for every personal occupation or topic under the sun.

Please ask the Mods to move the thread from the "General" subforum to the "Other" subforum.

 

[ArcticDude]

Thread moved to "Other" sub-forum

 

[Encap]

Thread moved to "Other" sub-forum

Thanks AD

 

[RA_pierce]

I have a virology related question:

What wavelength of UV is most effective for sterilizing surfaces of viruses, with specific regard to the coronavirus family?

260 nm is the peak absorption of DNA and for RNA it's 280 and I have access to lab equipment in this range (I do genomics research) but I wonder how the efficiency of sterilizing for a given wavelength is affected by the "container" of the genome.
A quick search through the literature leaves me with the impression that most of the research on this topic is specific to bacteria or viruses that contribute to common water-bourne illnesses.
Viruses and bacteria have varies "containers" for their genomes (cell walls or membranes for bacteria, capsid for viruses) so I wonder how these would affect the efficacy of these wavelengths (penetration and exposure time, for example).

 

[LaserMicroscope]

I have a virology related question:

What wavelength of UV is most effective for sterilizing surfaces of viruses, with specific regard to the coronavirus family?

260 nm is the peak absorption of DNA and for RNA it's 280 and I have access to lab equipment in this range (I do genomics research) but I wonder how the efficiency of sterilizing for a given wavelength is affected by the "container" of the genome.
A quick search through the literature leaves me with the impression that most of the research on this topic is specific to bacteria or viruses that contribute to common water-bourne illnesses.
Viruses and bacteria have varies "containers" for their genomes (cell walls or membranes for bacteria, capsid for viruses) so I wonder how these would affect the efficacy of these wavelengths (penetration and exposure time, for example).

Because coronaviruses are ssRNA viruses, the typical mechanism for nucleic acid damage via UV light (thiamine dimers) doesn't happen here. The typical wavelength for germicidal UV is (I believe) 253.7nm. For coronavirus, I would reccomend a dose of 12mJ/cm^2. Coronaviruses have both a lipid bilayer and a protein coat - it's less exact, but the lipid bilayer probably has an absorbance peak at around 450nm, and the protein coat has an absorbance peak around 280nm, so the typical germicidal wavelength shouldn't be appreciably absorbed by the protein or the membrane.

I did some quick math, and the formula I'd use to figure out if a particular germicidal UV treatment would be effective against coronavirus is given by:

{[power (mW) x exposure time (s)]/ treatment area (cm^2)} ≥ 12


Thanks for the question! I was happy to learn in doing more research that UV does have some promise for inactivating ssRNA, I suppose by exploiting the inherent weakness of its structure rather than the usual thiamine dimer mechanism.

 

[gazer101]

Can COVID-19 virions survive for >1 month suspended in a liquid residue (such as that on my parcel's packaging)? Don't worry, I used gloves and disinfected everything with 70% isopropyl alcohol

 

[Cyparagon]

What is a typical half life of active colonies, and how is it affected by temperature, humidity, and the type of contaminated surface?