For biologists studying the morphology of cells, electron microscopy (EM) is the method of choice with its nm resolution. However, the time necessary to acquire EM image series is long and often limits both the number and size of samples imaged. This paper presents a strategy for fast imaging and automated selection of regions of interest that significantly accelerates this process. In particular, this strategy involves scanning a tissue sample once, finding regions of interest in which target structures might be located, scanning these regions once again, and iterating the process until only relevant regions of the block face have been scanned repeatedly. For mitochondria and synapses, this approach is shown to produce near equal localization results to current state-of-the art techniques, and does so in almost a tenth of the time.