Fig. 2

Characterisation of swollen compartments in LITAF mutant fibroblasts. a T115N patient-derived fibroblasts were incubated with the endocytic tracer BSA-gold for 16 h, and followed by a 4 h chase period to load lysosomes with BSA-gold. Conventional electron microscopy reveals the presence of flocculated BSA-gold within electron dense portions of vacuolated compartments (arrowheads). b Control or LITAF mutant fibroblasts were incubated with fluid-phase HRP for 4 h before being fixed. A DAB reaction was performed on cells before being processed for conventional electron microscopy (further examples in Additional file 3: Fig. 3). c Cryo immunogold electron microscopy was performed on T115N patient fibroblasts. Labelling with anti-LAMP1 antibody shows vacuolated compartments to be LAMP1 positive, and labelling with anti-Cathepsin D antibodies reveals labelling on electron dense patches within the lumen of such swollen compartments