Supplementary 1: Microscope

Press the space bar to begin. This is intended to also be viewed under a microscope. Use Supplementary 1: Microscope Calibration for Teachers to get the  Snap stage coordinates of the pixels seen by your microscope (https://snap.berkeley.edu/snapsource/snap.html#present:Username=milliones&ProjectName=Supplementary%201%3A%20Microscope%20Calibration%20for%20Teachers).