How quickly should you get kidney stones to your doctor for analysis after passing them? I was given essentially zero instructions apart from being handled some strainers to go panning for gold and a sterile container I was told to put my findings in.
Your doctor wants to know what the stones are made of (e.g. Calcium oxalate, etc.) Being in the container will not be alter that, nor will drying out.
Just put all the stones you find in the container, and follow the advice you were given about fluids, foods, etc. Drop the stones off whenever it's convenient - a week or two is fine. The sooner they are analyzed, however, the sooner your doctor can give you tailored advice on measures you can take that will decrease the likelihood of more stones forming.