Figure 2.

Examples of immunostainings with titin antibodies flanking the PEVK region. (A and B) Immunofluorescence images of single psoas myofibrils stretched to different SLs (indicated on the right) and labeled with either the N2-A or the I20/I22 titin antibody (A) or both antibody types together (B). As secondary antibody, Cy-3-conjugated IgG was used. In B, the lower two images show the same myofibril both at high and moderate stretch; the spacing between two close fluorescent stripes indicates the length of the PEVK region. pc, phase-contrast images. (Scale bar, 5 μm.) (C) Immunoelectron micrographs of stretched psoas muscle sarcomeres stained with N2-A or I20/I22. The nanogold particles indicate the respective epitope positions (arrows). (Scale bar, 0.5 μm.)