Dataset of scanning electron microscopy images of freeze-dried Escherichia coli DH5α cells

This dataset comprises scanning electron microscopy (SEM) images of freeze-dried <i>Escherichia coli</i> DH5α cells. Sample preparation steps prior to imaging include a 100x dilution (with deionized water) of 15 hours old <i>E. coli</i> DH5α cells cultivated in LB Lennox medium at 37 ^oC and 230 rpm. Subsequently, 20 μL of the diluted culture broth was added to the carbon tape on the copper stub, and the sample was freeze dried for 24 hours. The sample was coated with platinum to reduce charging effects prior to SEM analysis. Most of the SEM images in this dataset were of low magnification at 15 kV accelerating voltage, and showed flakes of freeze-dried cells together with bright odd-shaped crystalline deposits. Increase in magnification revealed more in-depth morphology of the freeze-dried cells, but poor imaging conditions precluded the identification of clusters of freeze-dried <i>E. coli</i> cells. Finally, a single blurred image at 8000x magnification at 15 kV accelerating voltage revealed, in rough contours, the outline of freeze-dried <i>E. coli</i> cells in close-packed formation. Cells were of 1 μm length and had an intact rod-shape characteristic of <i>E. coli</i> DH5α. Overall, the result suggested that freeze-drying did not result in cell lysis or alter the morphology of <i>E. coli</i> DH5α.