An immunoelectron micrograph of a muscle larva
An immunoelectron micrograph of a muscle larva including stichocyte granules (α-granules, β-granules), which is immunostained with anti surface antibody (immunoaffinity purified using the worm surface), and secondary immunostained with anti rat IgG antibody (biotin tagged).  The immunoreaction is visualised by the third reaction with avidin -gold complex.

    tissue         muscle larva
    1 st antibody    anti surface antibody 
    2nd antibody    anti rat IgG antibody (biotin tagged)
    visual marker    colloidal gold   (avidin tagged)

Positive staining is observed on α-granules, but notβ-granules near α-granules, suggesting the worm surface and α-granules share antigenicity.