microscope B2

/ˈmaɪ.kɹəˌskoʊp/ magnifier of the image of small objects

micro B2

/ˈmaɪ.kɹoʊ/ Very small in scale or scope.

microbe B2

/ˈmaɪkɹoʊb/ Any microorganism; (loosely, nonscientifically) especially, a harmful bacterium.