Transmission electron microscopy of renal tubules generated in (a,c,e) CO
Independent Medium and (b,d,f) Leibovitz’s L-15 Medium for 13 days. Specimens fixed by (a,b) conventional glutaraldehyde show only bright tubule cells. In contrast, specimens fixed in (c-f) glutaraldehyde containing tannic acid reveal a heterogeneously composed epithelium consisting of bright and dark cells. e,f) High magnification shows intact bright and dark cells. The apical plasma membrane faces a lumen (arrow), while the basal side rests on a basal lamina (asterisk). Luminal and lateral plasma membranes are separated by a tight junction (arrow head).