Fig. 1. Peripherin particles, squiggles and longer IF. PC12 cells were fixed and processed for immunofluorescence at 0.5 hours (A-C), 2 hours (D-F) and 24 hours (G-I) after plating in DM. Peripherin particles and squiggles were apparent in regions between the nucleus and the cell surface between 0.5 and 2 hours (A-F; B and C are higher magnification views of the region denoted by the * in A; E and F are higher magnification views of the region indicated by the * in D). Longer IF were also present during this period. Growth cones and early neuritic processes, evident at 2 hours, also contained particles and squiggles (D-F). After 24 hours, a large number of longer peripherin IF were present in most regions of differentiated cells, and particles and squiggles were most obvious in growth cones [G-I; the growth cone region (*) in G is seen at higher magnifcations in H and I]. Panels J-L show GFP-peripherin in a cell fixed at 2 hours in DM. The GFP fluorescence is observed directly in J-K, and peripherin is observed indirectly by anti-peripherin stained with lissamine-rhodamine-conjugated goat anti-rabbit in L. The * in J represents the growth cone region seen in K and L. Bar, 10 µm in A,D,G,J; Bar, 5 µm in B,E,H,K,L; Bar, 2 µm in C,F,I.