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blahblahblah
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Posts: 1,022
Loc: South America
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Some words on effective sterilization ...
#1070879 - 11/20/02 04:16 PM (21 years, 4 months ago) |
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I have a book that I am reading now titled "Principle Methods of Sterilization in Health Sciences". Long title, interesting book (especially the mushroom aspect). The chapter I am on now explains Chemical Disinfection and has a list of disinfectants and a evaluation of their effectiveness on tubercle bacillus bacteria. (The purpose of using tubercle bacillus are the physical characteristics of this type of bacteria. It is exceptionally resistant to germicides and disinfectants, more so than most vegative bacteria. If tubercle bacillus bacteria is eliminated, it is a good bet that other vegative bacteria will be as well) The two types of bacteria we are most concerned about when it comes to disinfection and sterilization, TBC (tubercle bacillus, which produce spores) and vegative (which do not.)
The three most effective disinfectants are:
In reply to:
Alchohols 80%-90% Formaldehyde Glutaraldehyde
ALCOHOLS Eythl and isopropyl are much more effective as antiseptics than as disinfectants. Disinfectants can act only as long as they are in solution, and means that the alcohols become ineffectual as soon as they evaporate. Although this property has the advantage of leaving no residue on treated surfaces, it often makes repeated applications desirable in order to get adequate exposure.
FORMALDEHYDE Aqueous solutions are know as formalin. When purchased commercially formalin is a solution of approximately 40% formaldehyde in water. Therefore, 8% formaldehyde in 20% formaline. This high concentration is a high-level germicide, and its activity is further increased by adding alcohol. A combination of 8% formaldehyde and 70% isopropyl alcohol is rapidly bactericidal and even a sporicide. Sterility can be expected within 3 hours exposure. Its tuberculocidal action is extremely rapid. The irritating fumes of formaldehyde limit its usefulness (also its carcinogenic propertys ) and also its toxicity for tissue requires that instruments be rinsed thoroughly before use.
GLUTARALDEHYDE The chemical relative of fomaldehyde appears to be somewhat more effective than formaldehyde in that a 2% aqueous alkaline concentration has been reported as the approximate equivalent of 8% formaldehyde in alcohol. It is a high level disinfectant. Spores are destroyed within 3 hours and tuberculocidal (kills the living for of the bacteria) within a few minutes. It is also the liquid of choice for lensed instruments and certain critical items which should be sterile when used.
That should spark some ideas, I will update this if I remember :S
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blahblahblah
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Loc: South America
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Re: Some words on effective sterilization ... [Re: blahblahblah]
#1070893 - 11/20/02 04:19 PM (21 years, 4 months ago) |
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Edited by blahblahblah (11/21/02 01:39 PM)
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daussaulit
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Re: Some words on effective sterilization ... [Re: blahblahblah]
#1070928 - 11/20/02 04:28 PM (21 years, 4 months ago) |
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I pay $0.44 for a pint of rubbing alcohol. It hasn't failed me yet. Glutaraldehyde is really expensive compared to the alcohol.
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Suntzu
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Re: Some words on effective sterilization ... [Re: blahblahblah]
#1071139 - 11/20/02 05:29 PM (21 years, 4 months ago) |
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I think the bug you're talking about is Mycobacterium tuberculosis [maybe some other Mycobacteria]; I've never heard it called tubercle bacillus, do you know when that book was published? Just curious.
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blahblahblah
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Re: Some words on effective sterilization ... [Re: Suntzu]
#1071450 - 11/20/02 07:32 PM (21 years, 4 months ago) |
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These are ideas for COMPLETE sterilization. Alcohol works well or me too but I am making a mistake somewhere because I have about a 3% contamination rate. This is just some alternatives and information on effective complete sterilization for those interested.
The bacteria they are referring to is the tuberculosis, I read a little bit farther and they explained why they used that particular bacteria. I was just taking a guess at what it was The book was published in the mid 60's I believe so it is a little outdated. Should still be current with practices of today though. Thanks, any more thoughts or comments are welcome
Edited by blahblahblah (11/20/02 07:33 PM)
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dets
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Re: Some words on effective sterilization ... [Re: blahblahblah]
#1072735 - 11/21/02 03:32 AM (21 years, 4 months ago) |
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interesting
-------------------- "patriotism is the virtue of the vicious"
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Waldarbeiter
can you eat it?
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Re: Some words on effective sterilization ... [Re: blahblahblah]
#1073547 - 11/21/02 11:24 AM (21 years, 4 months ago) |
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Hi ! For anyone who doesn't know : 70% isopropyl is much more effective than 100% So don't waste your alcohol!
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Raadt
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Re: Some words on effective sterilization ... [Re: Waldarbeiter]
#1073587 - 11/21/02 11:45 AM (21 years, 4 months ago) |
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why is it more effective?
-------------------- Raadt -- The information I provide is only information from readings, growing of gourmet mushrooms, and second hand stories--
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Curious_George
You want abaloon?
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Re: Some words on effective sterilization ... [Re: Raadt]
#1073648 - 11/21/02 12:03 PM (21 years, 4 months ago) |
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anyone ever try potasium -metasulphite? ( spelling might be wrong but hey..suck it )
it's used in wine brewing, STRONG stuff, leaves no residue, cheap, i've been using it so far with good results, just because i have some.
cg
-------------------- ************************************.>>>>> Here Johny,, have a joint.. all your friends are doing it!!
Edited by Curious_George (11/21/02 12:04 PM)
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ExtravagantDream
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Re: Some words on effective sterilization ... [Re: Waldarbeiter]
#1073787 - 11/21/02 12:55 PM (21 years, 4 months ago) |
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I still havnt figured this out.. but the only conclusion i ever came to was that evaporates to fast. I read two links on this discussion in a previous post but it didnt state directly why, just that 70% was more efficient then anything above 85% i believe it was.
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blahblahblah
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Loc: South America
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Re: Some words on effective sterilization ... [Re: Curious_George]
#1073817 - 11/21/02 01:02 PM (21 years, 4 months ago) |
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Quote:
Hi ! For anyone who doesn't know : 70% isopropyl is much more effective than 100% So don't waste your alcohol!
I have heard that 90% is the best, a 10% water to alcohol works better than using a 100% alcohol, and probably better than a 70% because it is 20% stronger? I dunno
Quote:
why is it more effective?
effective adj 1: producing or capable of producing an intended result or having a striking effect
More effective then would be the ability to produce this result more efficiently or with less work and/or better results than normal sterilization technique
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ExtravagantDream
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Re: Some words on effective sterilization ... [Re: blahblahblah]
#1073855 - 11/21/02 01:15 PM (21 years, 4 months ago) |
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In reply to:
More effective then would be the ability to produce this result more efficiently or with less work and/or better results than normal sterilization technique
umm yes it would. But why are you analizing what the word means? We are wondering how 70% could do a better job. As in kill more bacteria, using less of it, or less exposure time.
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blahblahblah
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Re: Some words on effective sterilization ... [Re: ExtravagantDream]
#1073860 - 11/21/02 01:17 PM (21 years, 4 months ago) |
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that part of the reply wasnt to you
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ExtravagantDream
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Re: Some words on effective sterilization ... [Re: blahblahblah]
#1073870 - 11/21/02 01:20 PM (21 years, 4 months ago) |
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sooo.....
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daussaulit
Forgetful
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Re: Some words on effective sterilization ... [Re: blahblahblah]
#1073982 - 11/21/02 01:52 PM (21 years, 4 months ago) |
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>I have heard that 90% is the best, a 10% water to alcohol works better than using a 100% alcohol, and probably better than a 70% because it is 20% stronger?
70% has more power than the 91% alcohol. The lower water content helps bacteria bring up their protective endosperm faster. 70% has even more water so it slows down the protective barrier from being raised, giving alcohol more time to kill it.
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ExtravagantDream
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Re: Some words on effective sterilization ... [Re: daussaulit]
#1074405 - 11/21/02 03:44 PM (21 years, 4 months ago) |
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Quote:
70% has more power than the 91% alcohol. The lower water content helps bacteria bring up their protective endosperm faster. 70% has even more water so it slows down the protective barrier from being raised, giving alcohol more time to kill it.
Nigga Wha? Speak some English foo. 70% does not have more power than 90% at least not per part. Do a test, on different occasions drink some of each and tell me which one u get sicker from The higher water content makes some what sense, but could u explain it more in depth. The way I look at it is the more diluted the alcohol is the less alcohol is touching a particular bacteria at a certain time. As in if it was 100% water 100% of the surface of the bacteria is covered in water, as with 70% alc. 70% of the surface is coverd in alc. This seems like a lesser dose for the bacteria to handle then would be 91/99%. Obviously, this isnt really corect, so can you explain?
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daussaulit
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Re: Some words on effective sterilization ... [Re: ExtravagantDream]
#1074508 - 11/21/02 04:23 PM (21 years, 4 months ago) |
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Sorry, I meant endospore, not endosperm.
In response to limited nutrients or other harsh conditions, many bacteria survive by forming spores that resist the environmental stress. Spores preserve the bacterial DNA and remain alive but inactive. - Encarta
Alcohols are commonly used topical disinfectants. They effective against Gram + and Gram - bacteria, fungal spores, and enveloped viruses. Alcohols are not effective against bacterial spores and non-enveloped viruses. Alcohols require time to work and they do not penetrate organic material. - University of Nebraska
Note, bacteria can remain dormant for centuries. It can also survive decades being inside a freezer-dryer. It can also stand boiling water. Because the endospore is so protective, it's hard to kill.
Now, when the bacteria touches 91%-100% isopropyl alcohol(rubbing alcohol), because there is a very low water content. This will enable the bacteria to produce the spores very quickly because it is "stronger" and provides a harsher environment.
When the bacteria touches the 70% alcohol, it's not as "strong" or harsh to the bacteria. Because the conditions aren't as adverse, the production of the spores will be slower, allowing more time for the alcohol to kill the bacteria.
I tried searching for a link on it, but I can't find it. Maybe you can have better luck, but it's been known for a long time and has been published many times.
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ExtravagantDream
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Re: Some words on effective sterilization ... [Re: daussaulit]
#1074520 - 11/21/02 04:27 PM (21 years, 4 months ago) |
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Thanks, that helps alot. Although I wonder how MUCh of a difference this really makes. Ive been using 99% for a while now. Never gotten a contam. Maybe I'm just lucky. Maybe I'm just a bad ass
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daussaulit
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Re: Some words on effective sterilization ... [Re: ExtravagantDream]
#1074527 - 11/21/02 04:29 PM (21 years, 4 months ago) |
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Maybe the bacteria your killing aren't the types that produce endospores. Not all of them do. I'm pretty sure hospitals use 70% alcohol, not 91% or 99%. I'll stick with 70%, better safe than sorry.
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ExtravagantDream
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Re: Some words on effective sterilization ... [Re: daussaulit]
#1074535 - 11/21/02 04:34 PM (21 years, 4 months ago) |
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Indeed. I have alot of 99, you think I should add some water to them?
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