An immunohistochemical method for the detection of proteins in the vertebrate lens

Fluorescence immunohistochemistry has traditionally been difficult or impossible to perform on the vertebrate lens because of its extremely high protein content. Described here is a robust and rapid method for preparing and labeling vertebrate eyes for confocal microscopy. This technique has successfully been applied to localize proteins in the lens epithelium and capsule, as well as the primary and secondary fibers. This technique preserves tissue morphology and coupled with double and triple labeling, has allowed localization of proteins bound to plasma membrane, basement membrane, nucleus, endoplasmic reticulum as well as sub-nuclear compartments. In addition, the present technique has proven useful for fluorescent immunohistochemical analysis of diverse tissues including whole embryos, adult muscle, pancreas, and liver. This procedure allowed us to successfully localize a wide variety of antigens on diverse vertebrate tissues including the more challenging vertebrate lens.

An improved method for affinity probe localization in whole cells of filamentous fungi

The fungal cell wall, though phylogenetically variable, acts universally as a potent barrier to probing intracellular structures. Thus, the use of high-molecular-weight probes such as antibodies and lectins has proven a formidable challenge. We have devised a preparative method for use with various affinity probes that can be applied to a broad spectrum of filamentous fungal species and used for imaging whole cells. In this study, confocal imaging of whole-mount fungal hyphae after freeze substitution, methacrylate embedment/de-embedment, and infiltration with affinity probes has yielded remarkably improved renderings of the three-dimensional distribution of both microtubules (using antibodies against both alpha- and beta-tubulin) and concanavalin A binding sites. Using this protocol we have been able to document: (1) the three-dimensional distribution of microtubules in all regions of hyphae, (2) the presence of apparent foci for cytoplasmic microtubules, (3) persistent cytoplasmic microtubules during mitosis, and (4) a three-dimensional view of many compartments of the endomembrane system including Golgi-equivalent organelles and apical vesicles. The last result represents the first direct confirmation of apical vesicles comprising the Spitzenkörper.