Sorry I don't have all the answers but I guess the moral of the story is wash before wear or use... Borax seems to help a lot. Enzyme spray is another staple around my house. I spray it right on any cloth, sheets, carpet...
That is interesting about the polytene chromosomes... I didn't know chromosomes were "packaged" like that... If that's what they are, then I had a wad of them come out the nape of my neck. They weren't moving though. There was a clear paddle looking thing in there with them. Do you know what that is?