Immuno-transmission electron microscopy (TEM) is the
technique of choice for high-resolution localization of proteins
in fixed specimen. Here we introduce 2 novel methods
for the fixation of sections from cryo-immobilized
samples that result in excellent ultrastructural preservation.
These high-speed fixation techniques, both called
VIS2FIX, allow for a reduction in sample preparation time
from at least 1 week to only 8 h. The methods were validated
in immuno-TEM experiments on THP-1 monocytes,
human umbilical vein endothelial cells (HUVECs) and
Madin–Darby canine kidney (MDCK-II) cells. The fixation
and retention of neutral lipids is demonstrated, offering
unique prospects for the application of immuno-TEM in
the lipidomics field. Furthermore, the VIS2FIX methods
were successfully employed in correlative fluorescence
and electron microscopy.