flasking media... - Orchid Board

jaxorchidman · #1 08-10-2011, 03:30 PM

Do you used sterilized distilled water to make the agar media and then put it in the pressure cooker to sanitize everything or can you just make the media normal and then put it into the pressure cooker to sterilize everything? Thank you! I'm about to try some stem props as my first try.

Kelo · #2 08-10-2011, 03:40 PM

I think that if you used sterilised distilled water there would be a chance of infection before it came to a boil or reached boiling point therefore you could use unsterilised distilled water.

jaxorchidman · #3 08-10-2011, 04:34 PM

That's what I figured too Kelo. Even if the media has gelled up, it goes back to a liquid state after sterilization and gels back up again. I have 20 jars of media ready to go now. All I have to do now is build a laminar hood.

BikerDoc5968 · #4 08-10-2011, 06:23 PM

Ordinary tap water works just fine for making up the media. The whole point of putting the final preparation in a pressure cooker and sterilizing everything is to kill whatever bacterial/fungal contaminate might be lingering. I believe you have to cook it for about 15 to 20 minutes at 15#. So to start with sterile water makes no sense and you don't need distilled water unless possibly the TDS's of your tap water are high.

jaxorchidman · #5 08-10-2011, 06:45 PM

I used distiller water and then got the ph to about 5.2. I then warmed the media up to melt the agar. After that I fille my mason jars, slightly pit the lids on, pressure cooked at 15 psi for 15 mins. I have the lids of the mason jars upside down so they don't pressure seal. The reason behind that is when I go to open the culture vessel it would suck in air if the pressure seal is sealed. Does that make sense?

Kelo · #6 08-10-2011, 07:10 PM

Yes, that's right, I didn't employ a laminar hood which doesn't matter now as none of my seeds germinated but I still have a few pods maturing so I'm not defeated yet! lol

jaxorchidman · #7 08-14-2011, 03:35 PM

So, I noticed that there was some condensation on the inside of my culture vessels. I turned them upside down and water leaked out. I'm glad I did that otherwise all my vessels would have been contaminated.
To fix this I removed all the canning lids that I had turned upside down, drilled holes in them and stuck a round bandaid over the hole. After that I put the lids on correctly and resterilized them. Hopefully this will be okay. I'll update after errything has been completed.

Royal · #8 08-26-2011, 11:28 AM

You really need a good seal in order to keep contamination out of the prepared flasks. Venting the lids is definitely the way to go. I hope the band aids work for you. I use the "sterile spots" that the OSP sells, they really hold up well to the pressure cooker.

jaxorchidman · #9 08-26-2011, 02:13 PM

I used the breathable fabric spots from curad. Has worked great so far. I sowed Bc. Kosh Wallis yesterday and also did some stem propagation also. Updates here in a couple weeks. I love this scientific stuff. I might even build a laminar flow hood.