FlyTrapCare Forums

Iam fairly new to tc and I have only used agar.I just received a couple samples of gellum gum and Carrageenan.I was wondering if anyone has any experience with any of these and could give me any helpful advice.When I use agar I like the firmness of about 5.0to5.5 per liter and use mostly just 1/3 m.s.Iam thinking I should add 2-4g/L for the Gellum gum?For the Carrageenan powder I really have no clue?
Another question I have is how will these effect the p.h.I have normally put my p.h. at about 5.9 before adding the agar.
Below I added a photo of some heli.germination using 1/3ms and clouding agar.The seeds were placed on Oct.1 2012.And they were given to me from a very nice person on the forum.Many thanks.

thelarge wrote:Iam fairly new to tc and I have only used agar...Iam thinking I should add 2-4g/L for the Gellum gum?For the Carrageenan powder I really have no clue?

Your pictures look good !!! Love to try Heli when I have a chance. You're no longer "fairly new" Thelarge.

I just try 3g/l food grade gellan gum and love it. It's quite clear like water. According to Phyto, you can use 8 - 10 g/l for Carrageenan (never try it). It's more clarity than agar (sure) but may be less clear than gellan gum (could be wrong).

Hey thanks Kihn for the response.Sometimes its easier just to ask here instead of researching yourself.I did some replating today using the gellum gum.Iam very pleased with how it turned out.I went with 3g. and I think that was perfect.and I set the ph.at 5.8.I have always went a little higher on the ph.using the lab grade agar,I recall someone saying that the agar lowers ph.0.5 to 1.0 after autoclave.Still not sure about the gellum.Anyway,after using the gellum gum I wont go back to agar.I like not having to heat up the media before autoclave.Much more clarity.I will try the carrageenan next week.Heres a couple picks of todays replates.Sorry using my phone camera.

Tom,
If it works the same or better than agar I won't go back to agar too. smile

thelarge wrote: . . . and I set the ph.at 5.8.I have always went a little higher on the ph.using the lab grade agar,I recall someone saying that the agar lowers ph.0.5 to 1.0 after autoclave.Still not sure about the gellum.Anyway,after using the gellum gum I wont go back to agar.I like not having to heat up the media before autoclave.Much more clarity.I will try the carrageenan next week.Heres a couple picks of todays replates.Sorry using my phone camera.

Media prepared with 0.6% Difco Bacto Agar, with an initial pH of 5.7, fell to 4.6 after autoclaving; and fell even further to 4.4 after six weeks of storage. Liquid media was even more deeply affected.

Other components of media also serve to lower the post-autoclave pH, including the unrefrigerated storage of prepared media; unchelated ferrous sulfate in the case with acidic media (3-6); calcium nitrate in media with an initial pH of 6-9; and even the use of sucrose as a carbohydrate aids in acidification -- even more so with maltose, glucose or fructose. Acidification is also associated with the generally high levels of CO2 in the closed vessels; and with auxin-containing media in general . . .

Congratulations on the great looking cultures. I am very new to tc, but I wanted to mention that it seems that Carageenan does need to be heated some before autoclaving. My first batch was inconsistent due to not heating to fully dissolve.

I love Gelcarin and never change back to agar
I use 7g/ltr and it dont need to be heated. I mix my medias, dispense all in cold water and fill it in the jars
Easy job

Isn't Gelcarin and Carrageenan the same product? If so, I wonder why my consistancy wasn't good if you are having good luck with it. I'd love to not have to heat the media before autoclaving.

BigBella wrote:

thelarge wrote: . . . and I set the ph.at 5.8.I have always went a little higher on the ph.using the lab grade agar,I recall someone saying that the agar lowers ph.0.5 to 1.0 after autoclave.Still not sure about the gellum.Anyway,after using the gellum gum I wont go back to agar.I like not having to heat up the media before autoclave.Much more clarity.I will try the carrageenan next week.Heres a couple picks of todays replates.Sorry using my phone camera.

Media prepared with 0.6% Difco Bacto Agar, with an initial pH of 5.7, fell to 4.6 after autoclaving; and fell even further to 4.4 after six weeks of storage. Liquid media was even more deeply affected.

Other components of media also serve to lower the post-autoclave pH, including the unrefrigerated storage of prepared media; unchelated ferrous sulfate in the case with acidic media (3-6); calcium nitrate in media with an initial pH of 6-9; and even the use of sucrose as a carbohydrate aids in acidification -- even more so with maltose, glucose or fructose. Acidification is also associated with the generally high levels of CO2 in the closed vessels; and with auxin-containing media in general . . .

Hi David
this sound really good but I'm not 100% sure what the out come is , is it possible to elaborate a bit more in my English understanding please
J

Tom
good to see some of your jar's doing so well , I have been using carrageenan , and it works 100% better making up the media cold , and can be calved after adding it to the jars or even heated up then adding to the jars and calving, ,its a little cloudy but for me works well , use another agar, where you have to heat up the mix to dissolve the agar , and its a hazel to dissolve , but clarity is much higher, but no real difference in germination or growth in the jars here for me
so I like the carrageenan for ease of use , but would like to see what David says if he is able to tell me more from his last post too, as his knowledge and experience should be listened too with great interest .
J

Sounds like there are lots of diffrent things in our media that can change the ph.I wonder than how important it is to have a good ph.I have never tested the ph after autoclave but it seems I should have.

thelarge wrote:Sounds like there are lots of diffrent things in our media that can change the ph.I wonder than how important it is to have a good ph.I have never tested the ph after autoclave but it seems I should have.

For drosera seeds, it is somehow important. At least PH should not be high, low PH is okay. At high PH, seeds does not germinate for me. Untill PH drops by itself - which takes months sometimes - or untill transfered..
I am not stressing anymore about bigger droseras when replating them. Their former media is usualy low ph (roots covered with old gel), when you put those to new media ph changes instantly. It wont stay at same value as you set it.

I tried carregean with %30 MS, before AC I adjusted ph to 5,62. After sterilizing result was 6,53. I would use that batch on seeds, but changed my plan hehe..

I'm brand new to tissue culture. But I have some Carrageenan from doing water marbling fluid painting. I wonder do I need to mix anything with it other than ph adjusted water?

thelarge wrote:I did some replating today using the gellum gum.Iam very pleased with how it turned out.I went with 3g. and I think that was perfect.and I set the ph.at 5.8.I have always went a little higher on the ph.using the lab grade agar,I recall someone saying that the agar lowers ph.0.5 to 1.0 after autoclave.

I've had the same problem of low pH after autoclaving with the lab grade agar . The Gellum gum is a nice choice.

A few things after reading the posts.
1) some have used the terms carrageenan and gelcarin interchangably. Perhaps one is a brand name. There are different carrageenans floating around. The one that is being most heralded lately is called "high clarity carrageenan".
2) The medias that I make are all cold poured and at larger volumes (10L+), but with constant and vigorous agitation while dispensing. Gelling occurs with this method regardless whether using carrageenan, gellan gum, or agar.
3) Much hype has been giving to the starting pH vs post autoclaved. Looking at nutrient availability curves, and as long as your gel sets, I doubt that you will see a noticeable quality difference in the cultures with a starting pH anywhere from the mid fours to the mid sixes.
4) To solidify the same medium, about 3 times as much carrageenan is needed when compared to gellan gum. If someone is cost sensitive, some money can be saved with purchase of gellan gum...assuming the individual species responds similarly to the two gels.
5) I do not have experience with the high clarity carrageenans, but jars/tubes with gellan gum as the gelling agent are easier to clean.