I tried something similar and wrote about it in my book on your space with the basic stamp. Essentially, I put together Petri dishes with agar that was hot enough to sterilize it. Then I used to serve out to lift the top of the petri dish once the balloon was about 50,000 ft. Before the balloon burst the petri dish was closed. For comparison, I would keep one petri dish on the ground and send one up in the balloon. After recovery, see if there's a difference in the bacteria you see in both of the Petri dishes.

On Sat, Sep 19, 2020, 8:31 PM Larry <larry.phegley@...> wrote:

We are thinking about what project we want to take on this winter  We have considered streaming video from the balloon.  I really liked that idea but no one else did.  

So now we are thinking about attempting to capture bacteria in the stratosphere.  Has anyone done this?  From what we seem to be able to find it has been done very seldom.  We have access to a MD and a biochemist who are helping and we have read  4 or 5 papers from groups who have done it.  From talking with the biochemist I kind of sense there are textbook solutions to some of the problems of ensuring sterility.

Or dealing with the small amount of "life" we might find.

Larry

KJ6PBS