The Merkel cell carcinoma cell line, MS-1,  were grown to confluency. Cells were fixed with EM fixative (2% glutaraldehyde in 0.1 M cacodylate buffer) at room temperature for 1 hour and stored at 4 degrees. Fixed cells were sent to the Electron Microscope (EM) Laboratory, Advanced Technology Program at Frederick National Laboratory for Cancer Research, NCI for transmission electron microscopy (TEM) analysis of the paranuclear dot of intermediate filaments found in Merkel cell carcinoma.