The use of streptavidin conjugates as immunoblot loading controls and mitochondrial markers for use with Dictyostelium discoideum.

The loading controls used for quantitative immunoblotting of mammalian proteins are not appropriate for use with Dictyostelium discoideum. Actin levels, for example, change greatly during Dictyostelium development. In addition, Dictyostelium-specific antibodies for other potential control proteins are not commercially available. Here we demonstrate the use of labeled streptavidin to detect biotinylated mitochondrial 3-methylcrotonyl-CoA carboxylase α (MCCC1), providing a robust and convenient tool for quantitative normalization of Dictyostelium Western blots, as well as fluorescently labeling mitochondria for microscopy of fixed cells.