Experiment Hamster kidney cells were stably transfected with an expression vector containing the cDNA of human lysosomal acid phosphatase. Cells were processed for transmission electron microscopy and immunogold labeling using an antibody specific for acid phosphatase. The figure shows the immunoelectron microscopic image (L, lysosomes, scale bar, 0.5 um). Figure Source: Waheed, A., S. Gottschalk, A. Hille, C. Krentler, R. Pohlmann, T. Braulke, H. Hauser, H. Genze, K. von Figura. 1988. Human lysosomal acid phosphatase is transported as a transmembrane protein to lysosomes in transfected baby hamster kidney cells. EMBO J. 7: 2351-2358. Questions 1. Briefly describe the principle of immunogold labeling. 2. Characterize the distribution of acid phosphatase in the electron micrograph.