Today was mite testing day. Here's how it worked:
find a frame ideally with almost capped brood
alternatively one from brood chamber with "enough bees"
shake the bees from the frame into a small tub
pour or scoop 1/2 cup of (300) bees
put those in alcohol or windshield washer fluid in the test jar
swirl to kill bees and loosen mite's grip on bees
count mites
strain fluid and mites and swirl bees again
repeat until there are no mites
count mites
I don't have the data we collected, but the mite counts I did see looked every low. There were a couple of colonies that had low population and/or no brood. These were not tested.
There is another blog post with pictures about the process: Varroa Mite Inspection and Treatment