Except for the popcorn button, microwaves have not come very far in the past 20 years. And, since the day of the red thread you were supposed to somehow pull down the side of the bandaid to open it, bandaids have made little improvement either. While it is possible to apply a bandaid without ever having touched the gauze or adhesive, it is next to impossible.
I would defy anyone to open and apply eight bandaids "steriley" to a six month old and a five year old in rapid succession.
Wouldn't you be more likely to introduce bacteria into a phlebotomy site? Because the last time I remember, they simply wipe the area with an alcohol swab, insert the needs directly into a vein, then grab an opened 2 x 2 inch gauze, fold it in half and have you hold it while they apply a bandaid.