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Solipsis
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Using UV-C to create mutants & Radiation Dosage 1
#26533139 - 03/13/20 05:24 PM (4 years, 1 month ago) |
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At what dosage of radiation do cubensis spores more or less all get destroyed?
Or otherwise: how does that radiation dosage compare to the prescribed dosage for producing mutants? (Which is apparently about 6 mW / m2 / sec ).
There are many factors that together make it hard to just calculate the dosage my 15W lamp unit in my setup gives a plate at a certain distance.
If someone has some sort of a reference for me to approximate it enough or do a sort of calibration by killing spores or some other way, i'd love to hear it!
Edited by Solipsis (03/13/20 05:25 PM)
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murderlabz
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Re: Using UV-C to create mutants & Radiation Dosage [Re: Solipsis]
#26533325 - 03/13/20 07:01 PM (4 years, 1 month ago) |
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Edited by murderlabz (03/13/20 07:05 PM)
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PTreeDish
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Re: Using UV-C to create mutants & Radiation Dosage [Re: murderlabz]
#26557260 - 03/25/20 03:02 PM (4 years, 23 days ago) |
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The answer is highly variable depending on the wavelength, frequency and amplitude (power) of your UV lamp and the species. I've seen studies that use as little 15 mins for non-lethal mutagenesis in fungi.
UV light (254 nm) for 45 min is enough to kill off yeast. I've also read that certain fungi can take up to 6 hours to reach 80%+ lethality.
Did you buy your lamp online? The manufacturer could probably answer this question more precisely, especially if they marketed the lamp as germicidal.
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Solipsis
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Re: Using UV-C to create mutants & Radiation Dosage [Re: PTreeDish] 1
#26568482 - 03/31/20 05:48 AM (4 years, 18 days ago) |
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I do think I have a value for the power output of the actual light and it is something like 9.5 W iirc but i might not recall correctly. Would make it something like 65% efficient.
True it does depend on the spectrum as well. But there are additional factors regarding how much of the radiation even makes it to the plate.
My friend said it is too much to calculate or guesstimate and you need a UV meter. IDK if i can find one and maybe buy, use and resell.. or ideally just borrow from some lab...
So I don't think asking the manufacturer would help me figure out those other factors. If he says something it will probably be indeed about germicidal effectiveness and i wouldn't know how to translate this, would it be something like an LD50? Seems like different germs can also handle different amounts of UV before they die.
Thnx tho
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murderlabz
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Re: Using UV-C to create mutants & Radiation Dosage [Re: Solipsis]
#26570026 - 03/31/20 09:00 PM (4 years, 17 days ago) |
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Quote:
Solipsis said: My friend said it is too much to calculate or guesstimate and you need a UV meter. IDK if i can find one and maybe buy, use and resell.. or ideally just borrow from some lab...
ILT2400 UVGI Complete System For Measuring UV Germicidal/Disinfecting Light Sources
$2,900.00, ouch! very cool tho...
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PTreeDish
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Re: Using UV-C to create mutants & Radiation Dosage [Re: Solipsis]
#26570238 - 04/01/20 12:14 AM (4 years, 17 days ago) |
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More information is better than none. The bulb manufacturer will have the frequency, wavelength and will be able to confirm the power. They may already have a published paper with graphs or charts for different organisms that they had to have independently tested in order to make any marketed claims of disinfection.
If you get anything and want help deciphering, bring it here and share and at the least, I'll take a look and see there's anything we can find that gets you closer to being able to run your experiment.
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Solipsis
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Re: Using UV-C to create mutants & Radiation Dosage [Re: PTreeDish]
#26570500 - 04/01/20 06:57 AM (4 years, 17 days ago) |
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Fair enough thanks very much for offering to help.
Lemme do some digging.
edit:
- the product: https://www.lighting.philips.com/main/prof/conventional-lamps-and-tubes/special-lamps/purificationwater-and-air/commercial-and-professional-air/tuv-t8/928039004005_EU/product
- UV-C Radiation at 100 hr: 4.9 W [So no idea what the output is at 1 hr]
- "Spectral power distribution Colour" diagram apparently shows a wavelength of what seems to be 254 nm or at least very close to that. This is directly related to the frequency, right? So we don't need the frequency?
- The bulb is installed in my DIY flowhood, I built the cabinet but the laminar flow comes from an integrated device: a fan filter unit. In any case the bulb is installed at a height of about 55 cm. Probably irrelevant but it is attached to a flap in the 'ceiling' of the cabinet interior so that it irradiates a region in the cabinet but the working opening is shielded from direct irradiation, for added safety. Either way a plastic window covers this entire opening and is covered with a UV filter foil.
- I don't know if the scattering and reflections of the radiation are of any relevance, the 254 nm radiation as such is probably absorbed by most of the materials, I don't know if the flowhood filter itself would reemit it. Also don't know if that changes anything about the order of magnitude of irradiation.
- I tried to calculate how long i would need to irradiate a dish of a certain diameter but this gave me nonsense, like 2000 hrs. It seems that I don't know how to calculate the geometrics of what part of emitted radiation hits the dish.
If bringing a dish much closer to it so that there is only 10 cm distance would help, it would be good to know. I guess if you can calculate one scenario you can calculate another. And we can first see what 55 cm distance would mean and if it means such long exposure that we would want to shorten it.
Considering I have a reference for the target radiation exposure, can you help me figuring it out at least in theory, so that i might test it out and also see what happens if I make it say 3x as short exposure or 3x longer exposure than what we calculate in theory?
Edited by Solipsis (04/01/20 07:19 AM)
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PTreeDish
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Re: Using UV-C to create mutants & Radiation Dosage [Re: Solipsis]
#26571520 - 04/01/20 03:54 PM (4 years, 16 days ago) |
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OK - so your bulb is UV-C, meaning it has a really short wavelength and is a good candidate for inducing mutagenesis. Short waves also don't pass through materials very well. I wouldn't focus so much on distance as much as I would exposure time.
You'll obviously need to take it out of your hood so that you can place your experimental dishes in direct sight of the light. Please take precautions to avoid exposure to your eyes and skin. Never compromise personal safety - life is too short!
You're going to want to do what the researchers do and expose a variety of plates with varying exposure times. Make sure you maintain a control as a reference.
I found a great video of an amateur using UV light to induce mutagenesis in Oyster mushrooms:
Suggest watching this and then come back with your remaining questions.
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PTreeDish
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Re: Using UV-C to create mutants & Radiation Dosage [Re: Solipsis]
#26573008 - 04/02/20 10:40 AM (4 years, 16 days ago) |
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Let me know if you want to hop on a chat and look at some papers together. There are quite a few that I've found that provide the experiment setup for performing UV mutagenesis in mushrooms. We could review and discuss together. Might be a little tough with timezones but hit me up if it's even something you want to explore.
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Solipsis
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Re: Using UV-C to create mutants & Radiation Dosage [Re: PTreeDish]
#26576696 - 04/04/20 05:11 AM (4 years, 14 days ago) |
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There is already a direct line of sight to where I can put dishes, just not to where I would be standing.
I would want to know a ballpark / order of magnitude sort of exposure time and would also really appreciate hearing more about how to test it - test by checking what dosage of radiation kills everything vs where it does not kill everything?
And if you couldn't help with the ballpark exposure time I guess I could titrate it, first by big steps and then finetuning?
This is why I asked before if I can use that point of killing everything vs not everything as a reference for what is a good dosage for mutagenesis.
I think I mentioned this but my friend claimed I really need a UV meter otherwise it's just too difficult to know the dosage. I'm not so sure; I believe in clever solutions to do something like this anyway.
But idk if what I am proposing is feasible, I kinda need those rules of thumb so that I can use a reference that gives me direct result (killing everything or not) otherwise i would just need to spend too much time looking for the ultimate manifestations of mutations at all kinds of radiation dosages.
I will check out the video, thanks. Yeah I'm interested in working on it together, lemme also PM you.
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PTreeDish
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Re: Using UV-C to create mutants & Radiation Dosage [Re: Solipsis] 1
#26579764 - 04/05/20 03:22 PM (4 years, 12 days ago) |
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I did some research and think I have the answers to some of your questions. Take a look and let me know if this is what you were after.
1. How to calculate your lamps irradiance - the UV lamp power output over a given area
For this, A UV Intensity Meter would be helpful, but we can guesstimate. Based on the height you set the light, it will irradiate an area that is smaller when the lamp is closer and larger at taller heights.
As an example, let's presume the lamp is at a height such that it irradiates a 1m x 2m area = 2m2 (meters squared)
Irradiance: 4.9 W (your lamp wattage) / 2 (square meters) = 2.45 w/m2
2. Determine Your Power Exposure Titrations Let's say you want to test mutagenic effects across 4 different energy exposures, as measured by Joules over an area: 0, 100, 200, 300 J/m2
To find the time intervals, we need to convert the lamps irradiance units (Watts / Meters Squared) to Joules / Meters Squared.
If, Energy(J) = Power(W) × time(s) then time(s) = Energy(J) / Power(W)
0 = time(s) = 0 J/m2 / 2.45 w/m2 40.82s = time(s) = 100 J/m2 / 2.45 w/m2 81.63s = time(s) = 200 J/m2 / 2.45 w/m2 122.45s = time(s) = 300 J/m2 / 2.45 w/m2
3. What should the intervals be? Should I start with?
All the papers I found seem to use titration. If I were to do this, I'd do what you suggest which is to find what time intervals leads a lethal dose and work backwards from there.
4. Other Considerations
Studies and other posts here suggest that care must be taken to avoid allowing the natural DNA repair mechanisms to undo the damage caused by UV mutagenesis - which may include blocking all natural light post UV exposure all the way to fruiting.
Related Papers and Excerpts
Quote:
Mutation of the spores of Pleurotus sajor-caju yielded an extremely low-sporing mutant after 75 min exposure. The character has been found to be stable for more than 10 generations of subculturing. ... The spore mutation was conducted by exposing the spore suspension (in sterile distilled water) to u.v. radiation at variable time (15–120 min) intervals for LD99.
Development of sporeless/low sporing strains of Pleurotus through mutation
Quote:
A dilute suspension of each spore print was made in sterile distilled water taken in test tubes and exposed to ultraviolet rays giving 8 treatments at two distances (5 and 10 cm) from source for different time of exposure (10,15, 20 and 25 min). Irradiation was given under the dark conditions to avoid the process of photoreactivation.
Strain improvement in Pleurotus Ostreatus using UV light and ethyl methyl sulfonate as mutagens
Quote:
Ultraviolet (UV) light was used as a mutagen.The plates were irradiated with a Toshiba 10-W germicidal lamp 10cm apart for 17–22 s in the darkroom. The survival rate of protoplasts after this treatment was 1%–3%.
Isolation and characterization of a sporeless mutant in Pleurotus eryngii
Quote:
Plates were exposed to UV-C light in the dark for 0, 120, 240, or 360 J/m2 and growth was permitted for 3 d at 27 C. Unless otherwise stated all UV-C exposures were conducted using the UVP Mineralight R52 G (Upland, CA) between 200 and 280 nm (kmax = 254 nm) at an irradiance of 0.4 W/m2 as determined by a Blak-Ray Ultraviolet Intensity Meter model J225 (San Gabriel, CA).
https://scihub.bban.top/https://doi.org/10.1016/j.jip.2007.10.006
Most telling is the last one because it provides the math you need, coupled with your lamp, to determine to energy flux.
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leschampignons
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Re: Using UV-C to create mutants & Radiation Dosage [Re: Solipsis]
#26679030 - 05/18/20 01:42 PM (3 years, 10 months ago) |
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some nice info here
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Solipsis
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Re: Using UV-C to create mutants & Radiation Dosage [Re: leschampignons]
#26682736 - 05/20/20 07:29 AM (3 years, 10 months ago) |
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thank you PTree, we meet again xD i have been less active in some departments of the lab as i just need my facilities to be built before experimenting much more, but i will definitely take it to heart when i pick this UV-C stuff up a little later!
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PTreeDish
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Re: Using UV-C to create mutants & Radiation Dosage [Re: Solipsis]
#26684606 - 05/21/20 12:00 AM (3 years, 10 months ago) |
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Haha. I forgot all about this post.
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redshadow
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Re: Using UV-C to create mutants & Radiation Dosage [Re: Solipsis]
#26820315 - 07/13/20 12:10 AM (3 years, 9 months ago) |
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All dope info! I've been thinking about this lately. I feel like they have their advantages. They can be used in a SAB for example for a 5-10 min, given its low watts like 6W or less, after wiping it down but before you load up the thing up.
-------------------- =<{: Its only when you've lost everything that your free to do anything....... :}>=
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Solipsis
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Re: Using UV-C to create mutants & Radiation Dosage [Re: redshadow]
#26831842 - 07/19/20 02:56 AM (3 years, 8 months ago) |
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Apparently plastic dishes are too porous (or "low energy surface"?) for UV to penetrate by the way so i will prob give up on trying to sterilize and reuse plastic dishes...
It doesnt seem worth the work but acetic acid (like household vinegar) can apparently kill a lot of mold spores and penetrate...
Anyway the mutations i just havent gotten round to - doing tons of slants, until then i just havent gotten a handle on my collection yet all this time.
I did have an idea though, for titration of the UV dosage: I could make a setup with a shield cover hanging over an open dish on little rails, and then having the cover slowly move over the dish. Dimensions would be calibrated and graduated with lines/grid. The idea would be that with just one plate, a gradient of radiation exposure dosage could be created and the line where not everything died or got damaged too much could directly or indirectly show the optimal dosage of radiation, where growth would appear normal or could even be enhanced in select strains.
Even if it is not clear right away, just as with other forms of titration it could at least zoom and dial in to some narrow range which can then be titrated again with higher "resolution", for the fine dialing.
Seems like a fun project hopefully soon when i have a better handle on my culture management.
(sorry if someone else, or i myself have mentioned this idea before - i suffer from brain flatulence)
Edited by Solipsis (07/19/20 02:57 AM)
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Mrcloudy
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Re: Using UV-C to create mutants & Radiation Dosage [Re: Solipsis]
#26880899 - 08/14/20 11:54 PM (3 years, 7 months ago) |
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This is something that I would like to try as well when I can get around to it. I have a UVC lamp that I installed in my flowhood several years back.
-------------------- 10 different Ganoderma species from across the USA AMU MrCloudys guide to North American GanodermaUpdated A rough guide to North American Ganoderma species, with an emphasis on the laccate species.
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Jedicaps
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Re: Using UV-C to create mutants & Radiation Dosage [Re: Mrcloudy]
#26887154 - 08/18/20 05:27 PM (3 years, 7 months ago) |
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what i do know is 254nm wave length of UV-C is enough to kill(denature) COVID (sars)..so bear that in mind
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RatsboggleBiologic
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Edited by RatsboggleBiologic (10/19/20 05:21 PM)
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