Immunofluorescent analysis of 0.5% Triton X-100-permeabilized, teased fibers prepared from 4% paraformaldehyde-fixed, desheathed wild-type (WT) and Caspr2-knockout (Caspr2 KO) mouse sciatic nerves was performed using either a 1:1000 dilution of 366931 or pre-immune serum (Pre-Immune) and visualized with an Alexa Fluor® 488-conjugated anti-rabbit IgG secondary antibody (Green). Fluorescent staining of Caspr2 at the juxtaparanodal region around the nodes of Ranvier was observed. (Image courtesy of Dr. Elior Peles, Weizmann Institute of Science, Rehovot, Israel).