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ProfessorPinHead
Trapped in the Archives....




Registered: 07/09/10
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Re: What type of commercial agar is most suitable? [Re: Terry M]
#17484525 - 01/02/13 02:34 AM (11 years, 4 months ago) |
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Quote:
Terry M said: Is grade simply purity of the agar?
That's a good question. I would assume that is along the lines of what they are talking about.
I guess the way it works is the commercial suppliers get it in very large batches.
To help with longevity of the shelf life of the product they add preservatives along the way.
So if you get your agar from somewhere like the Asian food market it has likely sat around a long time. It has also gone through the hands of a middle man or two to get to the store.
Tic gums gets their agar directly from the source and according to them they use only the best quality agar they can get, that being 100% pure and additive free.
I believe that is where the 'pretested' comes from.
They test it and if there are any impurities in it they don't use it.
This is a good question though terry... I may call them today to get a more definitive answer on that one.
Either way I know I have tried tic gums agar and a number of other ones.
Take now agar for example.
They are both preservative free but the now agar is crap in comparison IME...
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Fischer
Teonanacatalyst


Registered: 06/03/10
Posts: 565
Loc: Downunder
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Re: What type of commercial agar is most suitable? [Re: Terry M]
#17484531 - 01/02/13 02:36 AM (11 years, 4 months ago) |
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I imagine it also has to do with the temperatures at which they hydrate fully and the temperature ranges they gel (or conversely, remain workable) at.
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OICU812
NC Tree Farm owner



Registered: 11/06/11
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Re: What type of commercial agar is most suitable? [Re: Fischer]
#17484689 - 01/02/13 03:53 AM (11 years, 4 months ago) |
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I'm a little confused here about cooking or pre-boiling agar before autoclaving. When I was at Aloha, they were using Stamets agar. They did not pre-boil or pre-heat, but simply mixed the agar and other components together and went straight into the autoclave. They always used a ratio of 20g/L.
I have been making mine this way ever since I returned from Aloha and the plates have been turning out well except for one instance when I reduced the amount of agar to 16g/L. In that case, I had partial jelling. Is the pre-boiling done to cause 100% of the agar to go into solution that would not otherwise occur? Am I getting incomplete hydration by not pre-boiling?
-------------------- -------------- "Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote!" --Benjamin Franklin "Those who give up liberty for security won't have, or deserve, either.". . . Benjamin Franklin ----> Read: The Fight of our Lives - Defeating the Ideological War Against the West - by Victor Davis Hanson
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Terry M
Stranger in a Strange Land



Registered: 06/18/10
Posts: 1,502
Loc: Rhode Island
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Re: What type of commercial agar is most suitable? [Re: ProfessorPinHead]
#17484877 - 01/02/13 06:28 AM (11 years, 4 months ago) |
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Quote:
ProfessorPinHead said: Take now agar for example.
They are both preservative free but the now agar is crap in comparison IME...
How did the crappiness show itself when you used this agar? I've never tried different agars, but just assumed they all jelled just fine, which is all they have to do. Though I can imagine that some need differing amounts of water than others to get the same degree of solidity.
Thanks, Terry
-------------------- Liberté, égalité, humidité.
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Sillyputty67

Registered: 10/06/12
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Re: What type of commercial agar is most suitable? [Re: Terry M]
#17484963 - 01/02/13 07:11 AM (11 years, 4 months ago) |
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From what Ive read, agar generally comes from two types of seaweed. Please pardon the lack of memory here.
1 type of agar seaweed is good for cooking etc.
1 type is good for lab cultures.
Generally youll find them mixed in most agars, and is probably what most of us are running at home.
The high quality lab agar is made only from the 1 type of quality seaweed. The Tic Gum's agar im assuming is made from the quality seaweed only.
-------------------- 1) Everything I ever posted or say is a lie.
Edited by Sillyputty67 (01/02/13 08:43 AM)
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Amanita virosa
botanist by day



Registered: 12/04/11
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Re: What type of commercial agar is most suitable? [Re: Sillyputty67]
#17485493 - 01/02/13 10:04 AM (11 years, 4 months ago) |
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Lab grade vs food grade agar. There is simply a purity standard for all lab grade reagents including agar which would be higher than say food grade or commercial grade reagents. Since we are sterilizing the agar the purity standard is somewhat irrelevant. If it gels well it's fine for agar work. I have been using food grade agar from www.bulkfoods.com @25/lb five lb minimum and it works great for all my agar work @ 18 grams/1000ml
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JML



Registered: 08/18/09
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Re: What type of commercial agar is most suitable? [Re: Amanita virosa]
#17485559 - 01/02/13 10:27 AM (11 years, 4 months ago) |
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I use stamets antibiotic MEA. Fungi.com
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ProfessorPinHead
Trapped in the Archives....




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Re: What type of commercial agar is most suitable? [Re: Amanita virosa]
#17485611 - 01/02/13 10:38 AM (11 years, 4 months ago) |
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Quote:
Amanita virosa said: Lab grade vs food grade agar. There is simply a purity standard for all lab grade reagents including agar which would be higher than say food grade or commercial grade reagents. Since we are sterilizing the agar the purity standard is somewhat irrelevant. If it gels well it's fine for agar work. I have been using food grade agar from www.bulkfoods.com @25/lb five lb minimum and it works great for all my agar work @ 18 grams/1000ml
I go with 20g / L ... Actually I never make that much. I always make 10g / 500ml.
I have never been to Aloha but talk on the phone with John every once in a while. He said about the same thing as OICU812 had mentioned to but the only difference was he told me about Tic GUms after mentioning FP. I am not positive about it but I think that may be where Paul gets his agar from. 
The only reason I melt them together before sterilizing is because I only run .5-1 liter at a time and it's nothing to pour some cold water into a pot and bring it to 180 degrees and stir it before loading it into the PC.
Obviously it distributes fine while sterilizing. I just do it mostly out of habit. For some reason I like to see the solution mixed properly before sealing the lid on the PC.
It literally takes all of 5 minutes.
Like AV said, lab grade agar is 100% pure agar. It has absolutely no fillers or preservatives at all.
Food grade is definitely fine for culture work so long as it is preservative free.
I have had some problems with food grade agar with preservatives in the past which is what led me to stat going with the high end stuff.
It is very expensive but the way I use it I only go through a pound a year and that is if I am busy so I don't mind spending a little extra on the good stuff. 
If any of you guys have actual businesses pertaining to fingi you can definitely get a free sample.
I own myco-tek.org and they sent me a pound to try when I first started using their agar.
Like I said up thread... After using it I wouldn't go back.
It actually smells different. Almost like bleach. It is some very clean stuff.
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Terry M
Stranger in a Strange Land



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Posts: 1,502
Loc: Rhode Island
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Re: What type of commercial agar is most suitable? [Re: ProfessorPinHead]
#17485736 - 01/02/13 11:06 AM (11 years, 4 months ago) |
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Quote:
Amanita virosa said: I have been using food grade agar from www.bulkfoods.com @25/lb five lb minimum and it works great for all my agar work.
I use their agar as well. I bought 5 pounds about a year and a half ago, and it looks like I've got around a pound of it left. I go through a lot of agar.
-------------------- Liberté, égalité, humidité.
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ProfessorPinHead
Trapped in the Archives....




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Re: What type of commercial agar is most suitable? [Re: Terry M]
#17485780 - 01/02/13 11:17 AM (11 years, 4 months ago) |
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That is a pretty good price, 
The 50 pound bag of RS-100 from Tic Gums works out to about 30 bucks a pound but that is 1/3rd more expensive than their regular food grade agar.
The food grade goes for about 1000 for a 50 pound bag so it is only 20 bucks a pound but you have to buy 50 pounds.
I don't know about a 50 pound bag sitting around,.
I might have to go in on it with someone for that order.....
I may order a 3 ounce jar of the BF agar just to try it out.
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OICU812
NC Tree Farm owner



Registered: 11/06/11
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Loc: Foothills of NC
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Re: What type of commercial agar is most suitable? [Re: JML]
#17486727 - 01/02/13 02:40 PM (11 years, 4 months ago) |
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Quote:
JML said: I use stamets antibiotic MEA. Fungi.com
Why antibiotic?
-------------------- -------------- "Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote!" --Benjamin Franklin "Those who give up liberty for security won't have, or deserve, either.". . . Benjamin Franklin ----> Read: The Fight of our Lives - Defeating the Ideological War Against the West - by Victor Davis Hanson
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ProfessorPinHead
Trapped in the Archives....




Registered: 07/09/10
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Re: What type of commercial agar is most suitable? [Re: OICU812]
#17486976 - 01/02/13 03:36 PM (11 years, 4 months ago) |
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It slows the growth of bacteria and other contams.
It is used to make isolating wild genetics from fruit bodies a little easier.....
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Fischer
Teonanacatalyst


Registered: 06/03/10
Posts: 565
Loc: Downunder
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Re: What type of commercial agar is most suitable? [Re: ProfessorPinHead]
#17487259 - 01/02/13 04:25 PM (11 years, 4 months ago) |
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Quote:
ProfessorPinHead said:I may order a 3 ounce jar of the BF agar just to try it out. 
I notice that TIC Gums has a place to request a sample. I wouldn't be a dick and do it just to try and score some free stuff, but if anyone were looking at finding/switching to a different product, that'd be a good way to see if it were worth the extra expense.
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JML



Registered: 08/18/09
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Re: What type of commercial agar is most suitable? [Re: ProfessorPinHead]
#17487449 - 01/02/13 05:02 PM (11 years, 4 months ago) |
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Quote:
ProfessorPinHead said: It slows the growth of bacteria and other contams.
It is used to make isolating wild genetics from fruit bodies a little easier.....
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OICU812
NC Tree Farm owner



Registered: 11/06/11
Posts: 1,064
Loc: Foothills of NC
Last seen: 3 years, 7 months
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Re: What type of commercial agar is most suitable? [Re: ProfessorPinHead]
#17487545 - 01/02/13 05:20 PM (11 years, 4 months ago) |
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Quote:
ProfessorPinHead said: It slows the growth of bacteria and other contams.
It is used to make isolating wild genetics from fruit bodies a little easier.....
Sounded like JML was using it as their general use agar. I have some also, but was taught not to use it unless contamination issues arose.
-------------------- -------------- "Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote!" --Benjamin Franklin "Those who give up liberty for security won't have, or deserve, either.". . . Benjamin Franklin ----> Read: The Fight of our Lives - Defeating the Ideological War Against the West - by Victor Davis Hanson
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Terry M
Stranger in a Strange Land



Registered: 06/18/10
Posts: 1,502
Loc: Rhode Island
Last seen: 9 years, 3 months
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Re: What type of commercial agar is most suitable? [Re: OICU812]
#17487623 - 01/02/13 05:38 PM (11 years, 4 months ago) |
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Quote:
OICU812 said: Sounded like JML was using it as their general use agar. I have some also, but was taught not to use it unless contamination issues arose.
Yup. Just like over-prescription of antibiotics for people. It encourages and promotes strains of antibiotic resistant bacteria, so you end up having worse bacteria problems overall.
-------------------- Liberté, égalité, humidité.
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Amanita virosa
botanist by day



Registered: 12/04/11
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Re: What type of commercial agar is most suitable? [Re: Terry M]
#17487679 - 01/02/13 05:48 PM (11 years, 4 months ago) |
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Quote:
Terry M said:
Quote:
OICU812 said: Sounded like JML was using it as their general use agar. I have some also, but was taught not to use it unless contamination issues arose.
Yup. Just like over-prescription of antibiotics for people. It encourages and promotes strains of antibiotic resistant bacteria, so you end up having worse bacteria problems overall.
ANd most of them don't work anyway, according to my micro bio buddy, because they are not heat stable. He swears its a joke to autoclave antibiotics then expect them to work. And this from a guy that has been studying antibiotics for 25 years. Anybody got any insite on that cause we had this long drawn out discussion about it today.
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Terry M
Stranger in a Strange Land



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Loc: Rhode Island
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Re: What type of commercial agar is most suitable? [Re: Amanita virosa] 1
#17487759 - 01/02/13 06:05 PM (11 years, 4 months ago) |
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Quote:
Amanita virosa said:
Quote:
Terry M said:
Quote:
OICU812 said: Sounded like JML was using it as their general use agar. I have some also, but was taught not to use it unless contamination issues arose.
Yup. Just like over-prescription of antibiotics for people. It encourages and promotes strains of antibiotic resistant bacteria, so you end up having worse bacteria problems overall.
ANd most of them don't work anyway, according to my micro bio buddy, because they are not heat stable. He swears its a joke to autoclave antibiotics then expect them to work. And this from a guy that has been studying antibiotics for 25 years. Anybody got any insite on that cause we had this long drawn out discussion about it today.
Yes, most antibiotics break down under heat. That's why the one specific antibiotic used for agar is gentamicin sulfate. This IS stable during sterilization.
-------------------- Liberté, égalité, humidité.
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Sillyputty67

Registered: 10/06/12
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Re: What type of commercial agar is most suitable? [Re: Terry M]
#17487817 - 01/02/13 06:15 PM (11 years, 4 months ago) |
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I saw one dude with a tek on here where he added fish aquarium antibiotic fresh outta the PC. Kinda like RR adds snake venom.
-------------------- 1) Everything I ever posted or say is a lie.
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Terry M
Stranger in a Strange Land



Registered: 06/18/10
Posts: 1,502
Loc: Rhode Island
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Re: What type of commercial agar is most suitable? [Re: Sillyputty67]
#17487894 - 01/02/13 06:34 PM (11 years, 4 months ago) |
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Quote:
malicom said: I saw one dude with a tek on here where he added fish aquarium antibiotic fresh outta the PC. Kinda like RR adds snake venom.
Yes, that's gentamicin sulfate. It's used to treat bacterial infections in fish.
-------------------- Liberté, égalité, humidité.
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