The performance of a moderately shorter fixation protocol for transmission electron microscopy (TEM) was evaluated by analyzing the cell structure quality after the processing. The relevance of this experimental technique is mainly based on reducting time of the steps of conventional protocols: fixation, washes, dehydration, and epoxy resin infiltration. Two sources of murine cells were used, the peritoneal and mesenteric lymph node cells. A fixation and material processing faster than usual methods can save time and improve results. Samples analysis indicated good preservation of different cell structures and organelles after this protocol.