Modifications have been made on the Ullberg technique of taking whole-body sagittal sections of frozen mice on Scotch tape. Three improvements are described which greatly increase the ease and reliability of taking the sections. The microtome is driven by a hydraulic system for a smooth, dependable stroke. The microtome stage has been redesigned to eliminate uneven sections. The cryostat is an ordinary, commercial freezer of the frost-free design which eliminates the need for defrosting and also maintains a lower humidity.