Re: sterilizing FF culture cups
My method is pretty similar to many mentioned, but a bit different too, so I thought I'd add some thoughts.
When a culture has stopped producing I freeze it. For 3 days, that's the time it takes to get spores and mite eggs (below zero F). I let them thaw for 15 minutes, which is long enough to thaw the very outside of the gross mess inside the cups. I can then "spin" the whole wad out in on piece. The stuff that clings: I let the cups sit for a few days (I wash once a week or two). The remaining gross matter is dry and can be removed by knocking the container on a table. Throw the flakes away.
I wash the cups and lids by hand with plain dish soap. The key is to wear Playtex gloves and wash (and rinse) in as hot of water as possible. I wash the lids first and use a sponge/scrubbie to clean the mesh with the sponge and the top with the scrubbie side. This takes off the sharpie date/species label off quite well in super hot water. The gloves make this possible.
Air dry and then spray with 70% isopropyl alcohol. a cheapo spray bottle works well. Get the surfaces wet with the rubbing alcohol, and then air dry again, stack and repeat. You can wipe off the alcohol with a tissue if you want but it should dry without residue.
91% isopropyl does not work better than 70% for surface sterilization, so save the buck a bottle. it's what I use with mushrooms and it works fine (easier on the skin as well).
I keep growing cultures in a completely different room than producing cultures (same with mushrooms, standard protocol) and haven't seen mites in quite some time.
Lots of good suggestions here, so I think the reader can pick and choose techniques that make sense for them.
Edit: I use micron filters for mushrooms in the jar stage, they are excellent but expensive, and likely overkill for fruit flies.
There's Bears in these here Woods. Wouldn't have it any other way.
Last edited by Ravage; 07-09-2019 at 10:52 PM.
Reason: additional thought