Scanning electron microscopy of cells and tissues under fully hydrated conditions.

A capability for scanning electron microscopy of wet biological specimens is presented. A membrane that is transparent to electrons protects the fully hydrated sample from the vacuum. The result is a hybrid technique combining the ease of use and ability to see into cells of optical microscopy with the higher resolution of electron microscopy.

Spatial and temporal association of Bax with mitochondrial fission sites, Drp1, and Mfn2 during apoptosis.

We find that Bax, a proapoptotic member of the Bcl-2 family, translocates to discrete foci on mitochondria during the initial stages of apoptosis, which subsequently become mitochondrial scission sites. A dominant negative mutant of Drp1, Drp1K38A, inhibits apoptotic scission of mitochondria, but does not inhibit Bax translocation or coalescence into foci. However, Drp1K38A causes the accumulation of mitochondrial fission intermediates that are associated with clusters of Bax.