Donate Now
and become
Forum Supporter.
Many perks! <...more...>
|
11-13-2010, 07:26 PM
|
Jr. Member
|
|
Join Date: Oct 2010
Posts: 18
|
|
Flasking - Somethings wrong here.
hi, Beginner here
I tried flasking Orchid seeds and what happened is that the media was pushed upwards in the Jars (Jam)
M not sure if vaccum or air was created under the media which caused space to form between the base and the media.
What am I doing wrong, Let me know please
Thanxz
A
|
11-14-2010, 07:43 AM
|
Senior Member
|
|
Join Date: Jul 2008
Zone: 8a
Location: West Midlands, UK
Age: 49
Posts: 25,462
|
|
Sorry I can't help. Just giving you a bump and I've also moved your post to the propagation forum as you may get more folks who can help see it over there.
|
11-14-2010, 07:54 AM
|
Senior Member
|
|
Join Date: Oct 2007
Zone: 7b
Posts: 3,623
|
|
same as Rosie by now, but adding that a picture of the flask and some more detailed explanation of what you have done would help a lot to identify any issues...
|
11-14-2010, 02:49 PM
|
Senior Member
|
|
Join Date: May 2009
Posts: 688
|
|
Mcfacker
The issue with the media in your flask probably has to do with the phenomenon of "superheated liquids."
Just google "superheated liquids." Even if this was not the cause, I will explain a little here, because readers may be making their own media & this is a safety issue of which you may not be aware.
This can occur with liquids heated to very high temps, either too long in a microwave oven or for different reasons in an autoclave/pressure cooker. Since you used jam jars, probably with metal covers, I assume you used a pressure cooker. Or maybe boiling water in an open pot. (flasking medium is a jell when cooled, but it is liquid when heated)
You can google good explanations of the causes & great dangers of superheated liquids in microwave ovens. While not mentioned, the phenomenon can also occur with autoclaves/pressure cookers &, maybe not superheated liquids but something lesser, in boiling pots. You can also study the laws of thermodynamics & their applications, if you really care to understand what's happening ... I'm not an expert on thermodynamics.
But here is some practical info. Think Temperature, Pressure, Volume, In pressure cookers, you are incresaing the Temp by introducing heat from a stove or burner. By venting the excess air in the chamber & continuing to heat, you are also increasing the pressure inside the chamber. By increasing temp & pressure, the contents of your jars experience very high temps. The volume of the liquid medium cannot really become smaller, but the increased pressure in the pressure chamber makes the liquid hotter than it would become under normal atmospheric pressure.
After you finished cooking the flasking jars filled with media, you may have wanted to quickly open your pressure cooker, so you may have vented the pressure relief valve too quickly. The pressure in the chamber QUICKLY became much lower than the pressure in the flask medium jar. The jar cover was on, but loose as it should have been. With pressure reduced, the superheated liquid in the jar "erupted" & moved upward in the jar.
You are fortunate that the eruption was contained inside the jar. If you are using a pressure cooker, always vent the pressure very slowly after cooking. Or, vent & let the cooker & contents cool down before opening. If you are opening & unloading a hot cooker & contents, give the pot a little shake first to release pressure from possible superheated liquids. Bubble-less liquids will actually start to boil in the container. Always wear thick leather gloves & a full face shield & use the pot cover as a shield. Superheated liquids in small mouthed ehrlenmeyer flasks can actually shoot up to the ceiling ... I am not exaggerating.
I'm not sure if boiling in an open pot can have the same results. Probably not, because of the lack of the issue of rapidly changing pressure.
Last edited by catwalker808; 11-14-2010 at 02:52 PM..
|
11-14-2010, 04:33 PM
|
Senior Member
|
|
Join Date: Oct 2007
Zone: 7b
Posts: 3,623
|
|
Catwalker, I think McFacker was talking about the already solified medium layer pushed upwards toward the cover, leaving some "air" space between it and the bottom of the flask... We had that when I was working in the lab, and was in most of the cases due to some fermenting contamination producing gases. That's why I asked to get a photo and better explanation of what s/he has done...
On the other hand, you have explained very well the situation with superheated liquids and the risks of cooking under high pressure... which nevertheless, should be kept in mind by everybody preparing flasking madia (or using a pressure cooker)
|
11-14-2010, 11:12 PM
|
Jr. Member
|
|
Join Date: Oct 2010
Posts: 18
|
|
[QUOTE=kavanaru;359224]Catwalker, I think McFacker was talking about the already solified medium layer pushed upwards toward the cover, leaving some "air" space between it and the bottom of the flask... We had that when I was working in the lab, and was in most of the cases due to some fermenting contamination producing gases. That's why I asked to get a photo and better explanation of what s/he has done...
QUOTE]
Thanxz Catwalker
Yes, I think this could be it, there is a layer of creamish liquid on top of my media, so most probably fermantation.
I used homemade media, since all other media are unavailable here in Fiji Islands. I used
TOMATO AND BANANA FORMULA
• 40 g of banana
• 100.0 ml of tomato juice
10.0 g of agar agar
• 20.0 g of sugar
• 1.2 g of Tiamina
• 900 ml of distilled water
this ofcourse was my first try at this, i found the media to be abit too solid and have moved Agar from 10g to abit over 7g/L. any suggestions you could make to avoid the fermenting contamination.
Btw. your Orchids on flicker look amazing - just wish I had access to a few. Thanxz
|
11-16-2010, 12:08 PM
|
Senior Member
|
|
Join Date: Jan 2008
Zone: 8a
Location: Piney Woods of East Texas
Age: 47
Posts: 3,253
|
|
Quote:
Originally Posted by Mcfacker
Yes, I think this could be it, there is a layer of creamish liquid on top of my media, so most probably fermantation.
...any suggestions you could make to avoid the fermenting contamination.
|
Sterilize in a pressure cooker or autoclave at 15 psi for 15 minutes. Prepared flasks should be totally sterile.
|
11-16-2010, 12:19 PM
|
Senior Member
|
|
Join Date: Oct 2007
Zone: 7b
Posts: 3,623
|
|
you can also sterilize your culture medium in the oven (easier than a pressuer cooker and you can seterilze more flask at one time!)
Here in this link you have a very well detailed process of culture pemiduim preparation, sterelization and seed growing...
Lotte & Thomas Orchids
|
11-16-2010, 01:35 PM
|
Senior Member
|
|
Join Date: Jan 2008
Zone: 8a
Location: Piney Woods of East Texas
Age: 47
Posts: 3,253
|
|
Quote:
Originally Posted by kavanaru
you can also sterilize your culture medium in the oven (easier than a pressuer cooker and you can seterilze more flask at one time!)
|
This can work sometimes, but they aren't "sterile". Unless under pressure, liquid can only be heated to 100 C before loosing heat energy to evaporation. Only pressure + heat can achieve temperatures to kill heat resistant spores and cysts.
If you have problems with contamination, making sure you start with totally sterile cultures is absolutely necessary. I've used the both the oven and a boiling water bath. Both had about 25% contamination - and that was with a prepared media. If you're making your own with fruits and veggies, I would only expect that rate to go up.
I'm all about making things work with the resources available, even if unconventional. But if you run into problems, the best way to solve them is to eliminate as many variables as possible.
|
11-20-2010, 07:10 PM
|
Jr. Member
|
|
Join Date: Oct 2010
Posts: 18
|
|
|
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
All times are GMT -4. The time now is 02:46 PM.
|