Figure 2.
From: Complete genome sequence of Anabaena variabilis ATCC 29413
Scanning electron micrograph of filaments of A. variabilis. Heterocysts are the larger cells with extracellular polysaccharide visible (indicated by the white arrows). Slender fibers are an artifact caused by the use of a glass fiber filter to support the cells on the membrane filter during washing. The length of the line is 20 µm.