We used new modalities in the field of cryo-electron microscopy, namely, cryo-focused ion beam milling and cryo-electron tomography  to capture the entire process of sporulation in Bacillus subtilis at a resolution of a few nanometers. We present a library of wild type sporangia at different stages of sporulation, engulfment mutants and antibiotic-treated sporulating cells. The purpose behind creating this library is for everyone to admire the heterogeneity that exists at a cellular level; how each cell in a population is different from the other even though they share the same genome and are grown in similar conditions. We hope to glean information about mechanism of operation of different machineries that mediate sporulation at a molecular resolution using these datasets.

We will continue to update the library as we acquire more tomograms during different growth conditions and of different strains of B. subtilis to understand the structural cell biology of sporulation.