sterilizing FF culture cups
I'm not sure if this is a good forum for this post but I wanted to pass on something that I have been doing for several years now that might help others with their culturing and reusing culture cups WITHOUT the mite carry over.
I had problems with culturing fruit flies and trying to reuse culture cups. I'm sure a lot of you have had this happen too. You start with strong cultures and after a few months of culturing your fruit fly cultures either seem to become weak in size and also a smaller and smaller hatch content.
I tried using mite paper, bleach wash on the cabinet surfaces but there always seemed to be an infestation of those dang tiny mites and I would have to buy new cultures and brand new culture cups, find a new cabinet space to start culturing again.
A couple years ago I started trying to sterilize the cups with each reuse and found that yes I could 'Steam" them in a microwave, wipe them down and try to clean the lids as thoroughly as possible but the mites just simply kept coming back.
I haven't found a way to keep them completely out of the culturing cycle but I did find a way to 'sterilize' the cups without all the prep of microwave and a way to safely clean the lids that always seemed to get so disgustingly dirty and clogged with the waste material from the fly cultures.
First I take and remove as much of the old culture material from the used cup, rinse out any loose material and flush the water. If you have enough cups and can wait until they have dried out you can easily empty the 'ruffy' into a plastic garbage bag so that you are not handling any of it.
I put the lids into the bottom of the sink and while filling the used cups up with hot water, I let the hot water run over the lids to soften up the discoloration on them.
Once the cups are filled, the lids will often already start to look white again, I take the top off of a generic mouth wash bottle and using the top I fill it about half full and pour it into each culture cup that I am going to clean. I then pour a generous amount of the same mouth wash on to the lid so that it will cover the vent material on the lid.
I let each stand for about a day (probably doesn't need to be 24 hours but it seems to also clear hazing that might have happened to the cup too)
The lids will have almost dried by this time but if you run hot water over them again it will take a couple minutes and they will almost rinse clean, I take a individual paper towel and gently scrub each lid.
With the culture cups I dump the wash into the toilet and refill them with hot water rinsing most of the remaining solid material off the sides, dump that into the toilet and then with a clean paper towel I will hand wipe the entire cup making sure that I also wipe out the top of the cup around the rim to be sure nothing has collected under the rim. Once I have wiped the cup completely clean I rinse it with fresh water and let it drain dry and move to the next cup to be cleaned.
Once you do this you can immediately go into culturing. I have yet to have this method cause any visible issue with the subsequent fruit fly culture and the lids will look almost brand new with no damage to the vent material.
You should be able to do this many many times with a culture cup and lid so you won't have to keep buying and throwing out cups. I've noticed a great improvement with my fruit fly cultures and the only 'negative' that I have run into is that after 5 or 6 cleanings the lid material can start to lift and/or the lid may crack along the outside edge (although I think this is more because of how I pull back a small opening to pour out flies for feeding)
Hope this helps, I might not have explained it in the easiest way but I think you can get my meaning.
All the best success with your cultures!
Lehmanni, Histronicus and Bullseye in the 1980's